diff --git a/src/Framework/Framework/Compilation/ControlTree/Resolved/ResolvedTreeRoot.cs b/src/Framework/Framework/Compilation/ControlTree/Resolved/ResolvedTreeRoot.cs
index 12aa8911cb..1255fb66b1 100644
--- a/src/Framework/Framework/Compilation/ControlTree/Resolved/ResolvedTreeRoot.cs
+++ b/src/Framework/Framework/Compilation/ControlTree/Resolved/ResolvedTreeRoot.cs
@@ -30,7 +30,8 @@ public class ResolvedTreeRoot : ResolvedControl, IAbstractTreeRoot
                 (from ds in Directives
                  from d in ds.Value
                  select (ds.Key, d.Value)).ToImmutableArray(),
-                GetViewModuleInfo() 
+                GetViewModuleInfo(),
+                CollectContentPlaceHolderIds()
             );
 
         private ViewModuleReferenceInfo? GetViewModuleInfo()
@@ -41,6 +42,33 @@ from d in ds.Value
                 return null;
         }
 
+        /// <summary>
+        /// Traverses the entire resolved tree (including controls inside templates) to collect
+        /// all ContentPlaceHolder IDs declared in this page/master page file.
+        /// </summary>
+        private ImmutableArray<string> CollectContentPlaceHolderIds()
+        {
+            var collector = new ContentPlaceHolderIdCollector();
+            this.AcceptChildren(collector);
+            return collector.Ids.ToImmutableArray();
+        }
+
+        private sealed class ContentPlaceHolderIdCollector : ResolvedControlTreeVisitor
+        {
+            public readonly List<string> Ids = new List<string>();
+
+            public override void VisitControl(ResolvedControl control)
+            {
+                if (control.Metadata.Type == typeof(ContentPlaceHolder)
+                    && control.Properties.TryGetValue(DotvvmControl.IDProperty, out var idSetter)
+                    && idSetter is ResolvedPropertyValue { Value: string id })
+                {
+                    Ids.Add(id);
+                }
+                DefaultVisit(control);
+            }
+        }
+
         public ResolvedTreeRoot(ControlResolverMetadata metadata, DothtmlNode node, DataContextStack dataContext, ImmutableDictionary<string, ImmutableList<IAbstractDirective>> directives, ControlBuilderDescriptor? masterPage)
             : base(metadata, node, null, dataContext)
         {
diff --git a/src/Framework/Framework/Compilation/ViewCompiler/ControlBuilderDescriptor.cs b/src/Framework/Framework/Compilation/ViewCompiler/ControlBuilderDescriptor.cs
index 83654e8c32..47b0427ee1 100644
--- a/src/Framework/Framework/Compilation/ViewCompiler/ControlBuilderDescriptor.cs
+++ b/src/Framework/Framework/Compilation/ViewCompiler/ControlBuilderDescriptor.cs
@@ -27,6 +27,12 @@ public class ControlBuilderDescriptor: IAbstractControlBuilderDescriptor
 
         public ViewModuleReferenceInfo? ViewModuleReference { get; }
 
+        /// <summary>
+        /// All ContentPlaceHolder IDs declared in this page/master page, including those inside CompositeControl templates.
+        /// Used to validate Content controls when performing master page composition.
+        /// </summary>
+        public ImmutableArray<string> ContentPlaceHolderIds { get; }
+
         ITypeDescriptor IAbstractControlBuilderDescriptor.DataContextType => new ResolvedTypeDescriptor(this.DataContextType);
 
         ITypeDescriptor IAbstractControlBuilderDescriptor.ControlType => new ResolvedTypeDescriptor(this.ControlType);
@@ -39,7 +45,8 @@ public ControlBuilderDescriptor(
             string? fileName,
             ControlBuilderDescriptor? masterPage,
             ImmutableArray<(string name, string value)> directives,
-            ViewModuleReferenceInfo? viewModuleReference
+            ViewModuleReferenceInfo? viewModuleReference,
+            ImmutableArray<string> contentPlaceHolderIds
         )
         {
             this.DataContextType = dataContextType;
@@ -48,6 +55,7 @@ public ControlBuilderDescriptor(
             this.MasterPage = masterPage;
             this.Directives = directives;
             this.ViewModuleReference = viewModuleReference;
+            this.ContentPlaceHolderIds = contentPlaceHolderIds;
         }
     }
 }
diff --git a/src/Framework/Framework/Controls/ContentPlaceHolder.cs b/src/Framework/Framework/Controls/ContentPlaceHolder.cs
index 19d223bcb2..d816825cc7 100644
--- a/src/Framework/Framework/Controls/ContentPlaceHolder.cs
+++ b/src/Framework/Framework/Controls/ContentPlaceHolder.cs
@@ -6,6 +6,7 @@
 using DotVVM.Framework.Binding;
 using DotVVM.Framework.Configuration;
 using DotVVM.Framework.Hosting;
+using DotVVM.Framework.Runtime;
 
 namespace DotVVM.Framework.Controls
 {
@@ -19,7 +20,49 @@ public ContentPlaceHolder()
         {
             SetValue(Internal.IsNamingContainerProperty, true);
         }
-        
+
+        protected internal override void OnInit(IDotvvmRequestContext context)
+        {
+            ResolvePendingComposition();
+
+            base.OnInit(context);
+        }
+
+        internal void ResolvePendingComposition()
+        {
+            if (ID == null) return;
+
+            // find the nearest master page 
+            var masterPage = GetAllAncestors()
+                .FirstOrDefault(a => a.IsPropertySet(Internal.PendingMasterPageCompositionsProperty, inherit: false));
+            if (masterPage == null)
+            {
+                throw new DotvvmControlException(this, "The ContentPlaceHolder or SpaContentPlaceHolder control can be used only in a master page. The current page doesn't have the @masterPage directive.");
+            }
+            
+            // check there are not multiple content placeholders with the same ID in the same master page (e.g. due to being inside a template that is instantiated multiple times)
+            var resolvedIds = (HashSet<string>)masterPage.GetValue(Internal.ResolvedMasterPageCompositionIdsProperty)!;
+            if (resolvedIds.Contains(ID))
+            {
+                throw new DotvvmControlException(this,
+                    $"The ContentPlaceHolder with ID '{ID}' has already been resolved. " +
+                    $"ContentPlaceHolder controls used for master page composition cannot be placed inside templates that are instantiated multiple times (e.g. Repeater, foreach).");
+            }
+
+            // find the pending composition
+            var pendingList = (List<PendingMasterPageComposition>)masterPage.GetValue(Internal.PendingMasterPageCompositionsProperty)!;
+            var pending = pendingList.SingleOrDefault(p => p.Content.ContentPlaceHolderID == ID);
+            if (pending != null)
+            {
+                // remove it from the master page and from the root
+                pendingList.Remove(pending);
+                resolvedIds.Add(ID);
+
+                // perform the deferred composition: wrap Content in a PlaceHolder and add it as our child
+                DefaultDotvvmViewBuilder.PlaceContentInContentPlaceHolder(pending.DataContextType, this, pending.Content);
+            }
+        }
+
         protected override void AddAttributesToRender(IHtmlWriter writer, IDotvvmRequestContext context)
         {
             // The ID is used only at runtime to find the PlaceHolder-Content pair.
diff --git a/src/Framework/Framework/Controls/Internal.cs b/src/Framework/Framework/Controls/Internal.cs
index 4d9a5c4547..df5f5281ba 100644
--- a/src/Framework/Framework/Controls/Internal.cs
+++ b/src/Framework/Framework/Controls/Internal.cs
@@ -7,6 +7,7 @@
 using DotVVM.Framework.Compilation;
 using DotVVM.Framework.Compilation.ControlTree;
 using DotVVM.Framework.Compilation.ControlTree.Resolved;
+using DotVVM.Framework.Controls.Infrastructure;
 using DotVVM.Framework.Hosting;
 
 namespace DotVVM.Framework.Controls
@@ -69,6 +70,16 @@ public class Internal
         public static DotvvmProperty UsedPropertiesInfoProperty =
             DotvvmProperty.Register<ControlUsedPropertiesInfo, Internal>(() => UsedPropertiesInfoProperty);
 
+        /// <summary>
+        /// This property is set on the master page root element and points to the root element of the child page. 
+        /// </summary>
+        public static readonly DotvvmProperty MasterPageChildPageProperty =
+            DotvvmProperty.Register<DotvvmControl?, Internal>(() => MasterPageChildPageProperty, defaultValue: null, isValueInherited: true);
+        public static readonly DotvvmProperty PendingMasterPageCompositionsProperty =
+            DotvvmProperty.Register<List<PendingMasterPageComposition>?, Internal>(() => PendingMasterPageCompositionsProperty, defaultValue: null, isValueInherited: true);
+        public static readonly DotvvmProperty ResolvedMasterPageCompositionIdsProperty =
+            DotvvmProperty.Register<HashSet<string>?, Internal>(() => ResolvedMasterPageCompositionIdsProperty, defaultValue: null, isValueInherited: true);
+
         public static bool IsViewCompilerProperty(DotvvmProperty property)
         {
             return property.DeclaringType == typeof(Internal);
@@ -105,4 +116,14 @@ public static TControl SetDataContextType<TControl>(this TControl control, DataC
             return control;
         }
     }
+
+    /// <summary>
+    /// Represents a Content control that has not yet been matched to a ContentPlaceHolder during master page composition.
+    /// The match is deferred until the ContentPlaceHolder is added to the control tree (e.g. when a CompositeControl builds its contents).
+    /// The list of <see cref="PendingMasterPageComposition"/> instances is maintained on the root of the master page, and must be copied down to all Content controls because the root is discarded during composition.
+    /// </summary>
+    internal sealed record PendingMasterPageComposition(Content Content, DotvvmView ContentPage, DotvvmView MasterPage, DataContextStack? DataContextType)
+    {
+        public string? MasterPageFile => MasterPage.GetValue(Internal.MarkupFileNameProperty)?.ToString();
+    }
 }
diff --git a/src/Framework/Framework/Hosting/DotvvmPresenter.cs b/src/Framework/Framework/Hosting/DotvvmPresenter.cs
index 6282f79d0d..172002ec82 100644
--- a/src/Framework/Framework/Hosting/DotvvmPresenter.cs
+++ b/src/Framework/Framework/Hosting/DotvvmPresenter.cs
@@ -13,6 +13,7 @@
 using DotVVM.Framework.Compilation.Binding;
 using DotVVM.Framework.Configuration;
 using DotVVM.Framework.Controls;
+using DotVVM.Framework.Controls.Infrastructure;
 using DotVVM.Framework.Runtime;
 using DotVVM.Framework.Runtime.Filters;
 using DotVVM.Framework.Security;
@@ -233,6 +234,10 @@ public async Task ProcessRequestCore(IDotvvmRequestContext context)
                     DotvvmControlCollection.InvokePageLifeCycleEventRecursive(page, LifeCycleEventType.Load, context);
                     await requestTracer.TraceEvent(RequestTracingConstants.LoadCompleted, context);
 
+                    // After Load, ensure all Content controls have been matched to their ContentPlaceHolders.
+                    // For postback requests, the Repeater creates children in Load (for Commands), so we check here.
+                    ValidateMasterPageComposition(page);
+
                     // invoke the postback command
                     var actionInfo = ViewModelSerializer.ResolveCommand(context, page);
 
@@ -267,6 +272,11 @@ public async Task ProcessRequestCore(IDotvvmRequestContext context)
                 // run the prerender phase in the page
                 DotvvmControlCollection.InvokePageLifeCycleEventRecursive(page, LifeCycleEventType.PreRender, context);
 
+                // After PreRender, ensure all Content controls have been matched to their ContentPlaceHolders.
+                // For GET requests, the Repeater creates children in PreRender, so this is the final check point.
+                // For postbacks, the check above after Load already caught most issues; this is a safety net.
+                ValidateMasterPageComposition(page);
+
                 // run the prerender complete phase in the page
                 DotvvmControlCollection.InvokePageLifeCycleEventRecursive(page, LifeCycleEventType.PreRenderComplete, context);
                 await requestTracer.TraceEvent(RequestTracingConstants.PreRenderCompleted, context);
@@ -598,5 +608,29 @@ public static bool DeterminePartialRendering(IHttpContext context) =>
         {
             return context.Request.Headers[HostingConstants.SpaContentPlaceHolderHeaderName];
         }
+
+        /// <summary>
+        /// Validates that all Content controls have been matched to their corresponding ContentPlaceHolder controls
+        /// after the Load phase. If any Content controls remain unmatched, it means the ContentPlaceHolder
+        /// was declared in the master page but never instantiated (e.g. a CompositeControl's GetContents was not called).
+        /// </summary>
+        private static void ValidateMasterPageComposition(DotvvmControl page)
+        {
+            var childPage = (DotvvmControl?)page;
+            while (childPage != null)
+            {
+                var pendingList = (List<PendingMasterPageComposition>)childPage.GetValue(Internal.PendingMasterPageCompositionsProperty)!;
+                if (pendingList is { Count: > 0 })
+                {
+                    var pending = pendingList[0];
+                    var masterPageInfo = pending.MasterPageFile is { } masterPageFile ? $" '{masterPageFile}'" : "";
+                    throw new DotvvmControlException(pending.Content,
+                        $"The ContentPlaceHolder with ID '{pending.Content.ContentPlaceHolderID}' was declared in the master page{masterPageInfo} but was never instantiated. " +
+                        $"Make sure the ContentPlaceHolder is always added to the control tree (e.g. it is not inside a conditional template).");
+                }
+
+                childPage = (DotvvmControl?)childPage.GetValue(Internal.MasterPageChildPageProperty);
+            }
+        }
     }
 }
diff --git a/src/Framework/Framework/Runtime/DefaultDotvvmViewBuilder.cs b/src/Framework/Framework/Runtime/DefaultDotvvmViewBuilder.cs
index f9814573b9..960bc3704e 100644
--- a/src/Framework/Framework/Runtime/DefaultDotvvmViewBuilder.cs
+++ b/src/Framework/Framework/Runtime/DefaultDotvvmViewBuilder.cs
@@ -7,7 +7,9 @@
 using System.Threading.Tasks;
 using DotVVM.Framework.Binding;
 using DotVVM.Framework.Compilation;
+using DotVVM.Framework.Compilation.ControlTree;
 using DotVVM.Framework.Compilation.Parser;
+using DotVVM.Framework.Compilation.ViewCompiler;
 using DotVVM.Framework.Configuration;
 using DotVVM.Framework.Controls;
 using DotVVM.Framework.Controls.Infrastructure;
@@ -51,7 +53,7 @@ public DotvvmView BuildView(IDotvvmRequestContext context)
                 var masterPage = (DotvvmView)pageBuilder.Value.BuildControl(controlBuilderFactory, context.Services);
 
                 FillsDefaultDirectives(masterPage);
-                PerformMasterPageComposition(contentPage, masterPage);
+                PerformMasterPageComposition(contentPage, masterPage, pageDescriptor);
 
                 masterPage.ViewModelType = contentPage.ViewModelType;
                 contentPage = masterPage;
@@ -99,40 +101,61 @@ private void FillsDefaultDirectives(DotvvmView page)
         /// <summary>
         /// Performs the master page nesting.
         /// </summary>
-        private void PerformMasterPageComposition(DotvvmView childPage, DotvvmView masterPage)
+        private void PerformMasterPageComposition(DotvvmView childPage, DotvvmView masterPage, ControlBuilderDescriptor masterPageDescriptor)
         {
             if (!masterPage.ViewModelType.IsAssignableFrom(childPage.ViewModelType))
                 throw new DotvvmControlException(childPage, $"Master page requires viewModel of type '{masterPage.ViewModelType}' and it is not assignable from '{childPage.ViewModelType}'.");
-
+            
             // find content place holders
             var placeHolders = GetMasterPageContentPlaceHolders(masterPage);
 
             // find contents
             var (contents, auxControls) = GetChildPageContents(childPage, placeHolders);
+            
+            // prepare the pending compositions list
+            // NB: this list is stored in the master page, so ContentPlaceHolders can access it easily thanks to DotVVM property inheritance - it will look up
+            var pendingCompositions = new List<PendingMasterPageComposition>();
+            masterPage.SetValue(Internal.PendingMasterPageCompositionsProperty, pendingCompositions);
+            masterPage.SetValue(Internal.ResolvedMasterPageCompositionIdsProperty, new HashSet<string>(StringComparer.Ordinal));
+
+            // save the reference to the child page
+            // NB: after the Load phase, we need to check the root master page and all nested master pages that all contents are resolved.
+            // This allows to jump from the root master page to the next nested one.
+            masterPage.SetValue(Internal.MasterPageChildPageProperty, childPage);
 
             // perform the composition
             foreach (var content in contents)
             {
+                // NB: when Contents are placed inside ContentPlaceHolders, the childPage is not part of the control tree anymore - it gets abandoned.
+                // Therefore, we need to copy all the important properties from the child page to the content control, so they are not lost during the composition.
+                // This will let potential ContentPlaceHolders inside the Content finding the list of pending compositions and the reference to the child page.
+                content.SetValue(DotvvmView.DirectivesProperty, childPage.Directives);
+                content.SetValue(Internal.MarkupFileNameProperty, childPage.GetValue(Internal.MarkupFileNameProperty));
+                content.SetValue(Internal.ReferencedViewModuleInfoProperty, childPage.GetValue(Internal.ReferencedViewModuleInfoProperty));
+                content.SetValue(Internal.MasterPageChildPageProperty, childPage.GetValue(Internal.MasterPageChildPageProperty));
+                content.SetValue(Internal.PendingMasterPageCompositionsProperty, childPage.GetValue(Internal.PendingMasterPageCompositionsProperty));
+                content.SetValue(Internal.ResolvedMasterPageCompositionIdsProperty, childPage.GetValue(Internal.ResolvedMasterPageCompositionIdsProperty));
+
                 // find the corresponding placeholder
+                var dataContextType = content.Parent!.GetDataContextType();
+
                 var placeHolder = placeHolders.SingleOrDefault(p => p.ID == content.ContentPlaceHolderID);
                 if (placeHolder == null)
                 {
-                    throw new DotvvmControlException(content, $"The placeholder with ID '{content.ContentPlaceHolderID}' was not found in the master page '{masterPage.GetValue(Internal.MarkupFileNameProperty)}'!");
+                    if (!masterPageDescriptor.ContentPlaceHolderIds.Contains(content.ContentPlaceHolderID!))
+                    {
+                        var masterPageInfo = masterPageDescriptor.FileName is { } masterPageFile ? $" '{masterPageFile}'" : "";
+                        throw new DotvvmControlException(content,
+                            $"The ContentPlaceHolder with ID '{content.ContentPlaceHolderID}' was not found in the master page{masterPageInfo}. " +
+                            $"Make sure that each Content element has a corresponding ContentPlaceHolder in the master page.");
+                    }
+
+                    pendingCompositions.Add(new PendingMasterPageComposition(content, childPage, masterPage, dataContextType));
+                    continue;
                 }
 
                 // replace the contents
-                var contentPlaceHolder = new PlaceHolder();
-                contentPlaceHolder.SetDataContextType(content.Parent!.GetDataContextType());
-                (content.Parent as DotvvmControl)?.Children.Remove(content);
-
-                placeHolder.Children.Clear();
-                placeHolder.Children.Add(contentPlaceHolder);
-
-                contentPlaceHolder.Children.Add(content);
-                content.SetValue(Internal.IsMasterPageCompositionFinishedProperty, true);
-                content.SetValue(DotvvmView.DirectivesProperty, childPage.Directives);
-                content.SetValue(Internal.MarkupFileNameProperty, childPage.GetValue(Internal.MarkupFileNameProperty));
-                content.SetValue(Internal.ReferencedViewModuleInfoProperty, childPage.GetValue(Internal.ReferencedViewModuleInfoProperty));
+                PlaceContentInContentPlaceHolder(dataContextType, placeHolder, content);
             }
 
             foreach (var control in auxControls)
@@ -142,6 +165,21 @@ private void PerformMasterPageComposition(DotvvmView childPage, DotvvmView maste
             masterPage.ViewModelType = childPage.ViewModelType;
         }
 
+        internal static void PlaceContentInContentPlaceHolder(DataContextStack? dataContextType, ContentPlaceHolder placeHolder, Content content)
+        {
+            var contentPlaceHolder = new PlaceHolder();
+            contentPlaceHolder.SetDataContextType(dataContextType);
+
+            ((DotvvmControl)content.Parent!).Children.Remove(content);
+
+            placeHolder.Children.Clear();
+            placeHolder.Children.Add(contentPlaceHolder);
+
+            contentPlaceHolder.Children.Add(content);
+
+            content.SetValue(Internal.IsMasterPageCompositionFinishedProperty, true);
+        }
+
         /// <summary>
         /// Gets the content place holders.
         /// </summary>
diff --git a/src/Samples/Common/DotvvmStartup.cs b/src/Samples/Common/DotvvmStartup.cs
index d263487d3e..3add781bba 100644
--- a/src/Samples/Common/DotvvmStartup.cs
+++ b/src/Samples/Common/DotvvmStartup.cs
@@ -33,6 +33,7 @@
 using DotVVM.Framework.ResourceManagement;
 using DotVVM.Samples.Common.Presenters;
 using DotVVM.Samples.Common.ViewModels.FeatureSamples.CustomPrimitiveTypes;
+using DotVVM.Samples.Common.Views.FeatureSamples.LateContentPlaceHolders;
 
 namespace DotVVM.Samples.BasicSamples
 {
@@ -269,6 +270,7 @@ private static void AddControls(DotvvmConfiguration config)
             config.Markup.AddCodeControls("cc", typeof(Controls.TextRepeater));
             config.Markup.AddCodeControls("cc", typeof(DerivedControlUsageValidationTestControl));
             config.Markup.AddCodeControls("PropertyUpdate", typeof(Controls.ServerRenderedLabel));
+            config.Markup.AddCodeControls("sample", typeof(TemplateContainerControl));
             config.Markup.AddMarkupControl("IdGeneration", "Control", "Views/FeatureSamples/IdGeneration/IdGeneration_control.dotcontrol");
             config.Markup.AddMarkupControl("FileUploadInRepeater", "FileUploadWrapper", "Views/ComplexSamples/FileUploadInRepeater/FileUploadWrapper.dotcontrol");
             config.Markup.AddMarkupControl("cc", "RecursiveTextRepeater", "Views/FeatureSamples/PostBack/RecursiveTextRepeater.dotcontrol");
diff --git a/src/Samples/Common/ViewModels/FeatureSamples/LateContentPlaceHolders/LateContentPlaceHolderViewModel.cs b/src/Samples/Common/ViewModels/FeatureSamples/LateContentPlaceHolders/LateContentPlaceHolderViewModel.cs
new file mode 100644
index 0000000000..27385c76e6
--- /dev/null
+++ b/src/Samples/Common/ViewModels/FeatureSamples/LateContentPlaceHolders/LateContentPlaceHolderViewModel.cs
@@ -0,0 +1,30 @@
+using System.Collections.Generic;
+using DotVVM.Framework.ViewModel;
+
+namespace DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders
+{
+    public class LateContentPlaceHolderViewModel : DotvvmViewModelBase
+    {
+    }
+
+    /// <summary>Viewmodel for Repeater tests - items list is set per subclass.</summary>
+    public abstract class RepeaterContentPlaceHolderViewModel : LateContentPlaceHolderViewModel
+    {
+        public List<string> Items { get; set; } = new List<string>();
+    }
+
+    public class RepeaterOneItemViewModel : RepeaterContentPlaceHolderViewModel
+    {
+        public RepeaterOneItemViewModel() { Items = new List<string> { "Item 1" }; }
+    }
+
+    public class RepeaterZeroItemsViewModel : RepeaterContentPlaceHolderViewModel
+    {
+        public RepeaterZeroItemsViewModel() { Items = new List<string>(); }
+    }
+
+    public class RepeaterMultipleItemsViewModel : RepeaterContentPlaceHolderViewModel
+    {
+        public RepeaterMultipleItemsViewModel() { Items = new List<string> { "Item 1", "Item 2" }; }
+    }
+}
diff --git a/src/Samples/Common/Views/ControlSamples/RouteLink/RouteLinkSpaUrlGen.dothtml b/src/Samples/Common/Views/ControlSamples/RouteLink/RouteLinkSpaUrlGen.dothtml
index 43f6751433..44b16e8661 100644
--- a/src/Samples/Common/Views/ControlSamples/RouteLink/RouteLinkSpaUrlGen.dothtml
+++ b/src/Samples/Common/Views/ControlSamples/RouteLink/RouteLinkSpaUrlGen.dothtml
@@ -1,17 +1,6 @@
 @viewModel DotVVM.Samples.BasicSamples.ViewModels.ControlSamples.RouteLink.RouteLinkUrlGenViewModel
-
-<!DOCTYPE html>
-<html xmlns="http://www.w3.org/1999/xhtml">
-<head>
-    <title>Hello from DotVVM!</title>
-    <style>
-        .invalid {
-            color: red;
-        }
-    </style>
-    <dot:RequiredResource Name="globalize:cs-CZ" />
-</head>
-<body>
+@masterPage Views/ControlSamples/RouteLink/RouteLinkSpaUrlGen.dotmaster
+<dot:Content ContentPlaceHolderID="ContentPlaceHolder">
     <div class="container">
         <h1>RouteLink SPA url generation demo</h1>
         <p>
@@ -61,7 +50,4 @@
                            Text="Server rendered: Optional prefixed parameter (at start)" data-ui="optional-prefix-parameter-at-start-server" />
         </p>
     </div>
-
-    <dot:SpaContentPlaceHolder ID="ContentPlaceHolder" />
-</body>
-</html>
+</dot:Content>
diff --git a/src/Samples/Common/Views/ControlSamples/RouteLink/RouteLinkSpaUrlGen.dotmaster b/src/Samples/Common/Views/ControlSamples/RouteLink/RouteLinkSpaUrlGen.dotmaster
new file mode 100644
index 0000000000..a43d5d5599
--- /dev/null
+++ b/src/Samples/Common/Views/ControlSamples/RouteLink/RouteLinkSpaUrlGen.dotmaster
@@ -0,0 +1,17 @@
+@viewModel DotVVM.Samples.BasicSamples.ViewModels.ControlSamples.RouteLink.RouteLinkUrlGenViewModel
+
+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+    <title>Hello from DotVVM!</title>
+    <style>
+        .invalid {
+            color: red;
+        }
+    </style>
+    <dot:RequiredResource Name="globalize:cs-CZ" />
+</head>
+<body>
+    <dot:SpaContentPlaceHolder ID="ContentPlaceHolder" />
+</body>
+</html>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/AuthViewContent.dothtml b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/AuthViewContent.dothtml
new file mode 100644
index 0000000000..9ab53d0e84
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/AuthViewContent.dothtml
@@ -0,0 +1,6 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/AuthViewMaster.dotmaster
+
+<dot:Content ContentPlaceHolderID="AuthContent">
+    <p data-ui="auth-content">Content from ContentPlaceHolder inside AuthenticatedView template</p>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/AuthViewMaster.dotmaster b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/AuthViewMaster.dotmaster
new file mode 100644
index 0000000000..a238c1bfa4
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/AuthViewMaster.dotmaster
@@ -0,0 +1,27 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+<!DOCTYPE html>
+
+<html lang="en" xmlns="http://www.w3.org/1999/xhtml">
+<head>
+    <meta charset="utf-8" />
+    <title>Late ContentPlaceHolder - AuthenticatedView Master</title>
+</head>
+<body>
+    <h1 data-ui="master-heading">AuthenticatedView Master Page</h1>
+
+    <%-- Same ContentPlaceHolder ID in both templates - only one will be instantiated --%>
+    <dot:AuthenticatedView>
+        <AuthenticatedTemplate>
+            <div data-ui="authenticated-section">
+                <dot:ContentPlaceHolder ID="AuthContent" />
+            </div>
+        </AuthenticatedTemplate>
+        <NotAuthenticatedTemplate>
+            <div data-ui="not-authenticated-section">
+                <dot:ContentPlaceHolder ID="AuthContent" />
+            </div>
+        </NotAuthenticatedTemplate>
+    </dot:AuthenticatedView>
+
+</body>
+</html>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Content.dothtml b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Content.dothtml
new file mode 100644
index 0000000000..c1f7baddbc
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Content.dothtml
@@ -0,0 +1,6 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/Nested.dotmaster
+
+<dot:Content ContentPlaceHolderID="NestedContent">
+    <h3 data-ui="page-content">Page Content - Late ContentPlaceHolder works!</h3>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/ContentWithDefault.dothtml b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/ContentWithDefault.dothtml
new file mode 100644
index 0000000000..cadf393170
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/ContentWithDefault.dothtml
@@ -0,0 +1,2 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/Nested.dotmaster
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/MismatchedContent.dothtml b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/MismatchedContent.dothtml
new file mode 100644
index 0000000000..1ed24283d1
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/MismatchedContent.dothtml
@@ -0,0 +1,9 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/Nested.dotmaster
+
+<dot:Content ContentPlaceHolderID="NestedContent">
+    <h3>This content matches correctly</h3>
+</dot:Content>
+<dot:Content ContentPlaceHolderID="NonExistentPlaceHolder">
+    <p>This content does NOT have a matching ContentPlaceHolder - should throw!</p>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Nested.dotmaster b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Nested.dotmaster
new file mode 100644
index 0000000000..823771db4a
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Nested.dotmaster
@@ -0,0 +1,13 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/Root.dotmaster
+
+<dot:Content ContentPlaceHolderID="RootContent">
+    <h2>Nested Master Page</h2>
+    <sample:TemplateContainerControl>
+        <ContentTemplate>
+            <dot:ContentPlaceHolder ID="NestedContent">
+                <p data-ui="default-nested-content">Default nested content</p>
+            </dot:ContentPlaceHolder>
+        </ContentTemplate>
+    </sample:TemplateContainerControl>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/NestedSameId.dotmaster b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/NestedSameId.dotmaster
new file mode 100644
index 0000000000..aea58987ed
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/NestedSameId.dotmaster
@@ -0,0 +1,14 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/Root.dotmaster
+
+<dot:Content ContentPlaceHolderID="RootContent">
+    <h2>Nested Master Page (shared ID)</h2>
+    <sample:TemplateContainerControl>
+        <ContentTemplate>
+            <%-- Same ID as the root ContentPlaceHolder to test same-ID nesting --%>
+            <dot:ContentPlaceHolder ID="RootContent">
+                <p data-ui="default-shared-content">Default shared-ID content</p>
+            </dot:ContentPlaceHolder>
+        </ContentTemplate>
+    </sample:TemplateContainerControl>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterMaster.dotmaster b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterMaster.dotmaster
new file mode 100644
index 0000000000..b9d1a1663d
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterMaster.dotmaster
@@ -0,0 +1,11 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.RepeaterContentPlaceHolderViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/Root.dotmaster
+
+<dot:Content ContentPlaceHolderID="RootContent">
+    <h2 data-ui="master-heading">Repeater Master Page</h2>
+
+    <dot:Repeater DataSource="{value: Items}" RenderSettings.Mode="Server" RenderWrapperTag="false">
+        <dot:ContentPlaceHolder ID="RepeaterContent" DataContext="{value: _root}" />
+    </dot:Repeater>
+
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterMultipleItems.dothtml b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterMultipleItems.dothtml
new file mode 100644
index 0000000000..ace24a3580
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterMultipleItems.dothtml
@@ -0,0 +1,6 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.RepeaterMultipleItemsViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/RepeaterMaster.dotmaster
+
+<dot:Content ContentPlaceHolderID="RepeaterContent">
+    <p data-ui="repeater-item">{{value: Items.Count}}</p>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterOneItem.dothtml b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterOneItem.dothtml
new file mode 100644
index 0000000000..6366bbe407
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterOneItem.dothtml
@@ -0,0 +1,6 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.RepeaterOneItemViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/RepeaterMaster.dotmaster
+
+<dot:Content ContentPlaceHolderID="RepeaterContent">
+    <p data-ui="repeater-item">{{value: Items[0]}}</p>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterZeroItems.dothtml b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterZeroItems.dothtml
new file mode 100644
index 0000000000..57da701002
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/RepeaterZeroItems.dothtml
@@ -0,0 +1,6 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.RepeaterZeroItemsViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/RepeaterMaster.dotmaster
+
+<dot:Content ContentPlaceHolderID="RepeaterContent">
+    <p data-ui="repeater-item">{{value: Items.Count}}</p>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Root.dotmaster b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Root.dotmaster
new file mode 100644
index 0000000000..34683aa83b
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/Root.dotmaster
@@ -0,0 +1,19 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+<!DOCTYPE html>
+
+<html lang="en" xmlns="http://www.w3.org/1999/xhtml">
+<head>
+    <meta charset="utf-8" />
+    <title>Late ContentPlaceHolder - Root</title>
+</head>
+<body>
+    <h1>Root Master Page</h1>
+
+    <sample:TemplateContainerControl>
+        <ContentTemplate>
+            <dot:ContentPlaceHolder ID="RootContent" />
+        </ContentTemplate>
+    </sample:TemplateContainerControl>
+
+</body>
+</html>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/SharedIdContent.dothtml b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/SharedIdContent.dothtml
new file mode 100644
index 0000000000..afcce0b900
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/SharedIdContent.dothtml
@@ -0,0 +1,6 @@
+@viewModel DotVVM.Samples.Common.ViewModels.FeatureSamples.LateContentPlaceHolders.LateContentPlaceHolderViewModel, DotVVM.Samples.Common
+@masterPage Views/FeatureSamples/LateContentPlaceHolders/NestedSameId.dotmaster
+
+<dot:Content ContentPlaceHolderID="RootContent">
+    <h3 data-ui="shared-id-page-content">Shared ID Page Content</h3>
+</dot:Content>
diff --git a/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/TemplateContainerControl.cs b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/TemplateContainerControl.cs
new file mode 100644
index 0000000000..b9fbee8b65
--- /dev/null
+++ b/src/Samples/Common/Views/FeatureSamples/LateContentPlaceHolders/TemplateContainerControl.cs
@@ -0,0 +1,23 @@
+using DotVVM.Framework.Binding;
+using DotVVM.Framework.Controls;
+
+namespace DotVVM.Samples.Common.Views.FeatureSamples.LateContentPlaceHolders
+{
+    /// <summary>
+    /// A simple CompositeControl with an ITemplate property.
+    /// The template is instantiated in GetContents (Load phase), allowing ContentPlaceHolder
+    /// controls defined inside the template to be created after the initial master page composition.
+    /// </summary>
+    public class TemplateContainerControl : CompositeControl
+    {
+        public static DotvvmControl GetContents(
+            ITemplate contentTemplate
+        )
+        {
+            return new HtmlGenericControl("div")
+                .AppendChildren(
+                    new TemplateHost() { Template = contentTemplate }
+                );
+        }
+    }
+}
diff --git a/src/Samples/Tests/Abstractions/SamplesRouteUrls.designer.cs b/src/Samples/Tests/Abstractions/SamplesRouteUrls.designer.cs
index d962e32e67..89b8e38d88 100644
--- a/src/Samples/Tests/Abstractions/SamplesRouteUrls.designer.cs
+++ b/src/Samples/Tests/Abstractions/SamplesRouteUrls.designer.cs
@@ -316,6 +316,14 @@ public partial class SamplesRouteUrls
         public const string FeatureSamples_MarkupControl_StaticCommandInMarkupControlCallingRegularCommand = "FeatureSamples/MarkupControl/StaticCommandInMarkupControlCallingRegularCommand";
         public const string FeatureSamples_ModalDialog_ModalDialog = "FeatureSamples/ModalDialog/ModalDialog";
         public const string FeatureSamples_NestedMasterPages_Content = "FeatureSamples/NestedMasterPages/Content";
+        public const string FeatureSamples_LateContentPlaceHolders_Content = "FeatureSamples/LateContentPlaceHolders/Content";
+        public const string FeatureSamples_LateContentPlaceHolders_MismatchedContent = "FeatureSamples/LateContentPlaceHolders/MismatchedContent";
+        public const string FeatureSamples_LateContentPlaceHolders_SharedIdContent = "FeatureSamples/LateContentPlaceHolders/SharedIdContent";
+        public const string FeatureSamples_LateContentPlaceHolders_ContentWithDefault = "FeatureSamples/LateContentPlaceHolders/ContentWithDefault";
+        public const string FeatureSamples_LateContentPlaceHolders_RepeaterOneItem = "FeatureSamples/LateContentPlaceHolders/RepeaterOneItem";
+        public const string FeatureSamples_LateContentPlaceHolders_RepeaterZeroItems = "FeatureSamples/LateContentPlaceHolders/RepeaterZeroItems";
+        public const string FeatureSamples_LateContentPlaceHolders_RepeaterMultipleItems = "FeatureSamples/LateContentPlaceHolders/RepeaterMultipleItems";
+        public const string FeatureSamples_LateContentPlaceHolders_AuthViewContent = "FeatureSamples/LateContentPlaceHolders/AuthViewContent";
         public const string FeatureSamples_NoJsForm_NoJsForm = "FeatureSamples/NoJsForm/NoJsForm";
         public const string FeatureSamples_NullHandling_Button_Enabled = "FeatureSamples/NullHandling/Button_Enabled";
         public const string FeatureSamples_ParameterBinding_OptionalParameterBinding = "FeatureSamples/ParameterBinding/OptionalParameterBinding";
diff --git a/src/Samples/Tests/Tests/Feature/LateContentPlaceHoldersTests.cs b/src/Samples/Tests/Tests/Feature/LateContentPlaceHoldersTests.cs
new file mode 100644
index 0000000000..4fe3124575
--- /dev/null
+++ b/src/Samples/Tests/Tests/Feature/LateContentPlaceHoldersTests.cs
@@ -0,0 +1,125 @@
+using DotVVM.Samples.Tests.Base;
+using DotVVM.Testing.Abstractions;
+using Riganti.Selenium.Core;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace DotVVM.Samples.Tests.Feature
+{
+    public class LateContentPlaceHoldersTests : AppSeleniumTest
+    {
+        [Fact]
+        [SampleReference(nameof(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_Content))]
+        public void Feature_LateContentPlaceHolders_ContentPlaceHolderInTemplate()
+        {
+            RunInAllBrowsers(browser => {
+                browser.NavigateToUrl(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_Content);
+
+                browser.First("h1"); // root master page
+                browser.First("h2"); // nested master page
+                var pageContent = browser.First("[data-ui='page-content']");
+                AssertUI.InnerTextEquals(pageContent, "Page Content - Late ContentPlaceHolder works!");
+            });
+        }
+
+        [Fact]
+        [SampleReference(nameof(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_SharedIdContent))]
+        public void Feature_LateContentPlaceHolders_SameContentPlaceHolderIdInRootAndNested()
+        {
+            RunInAllBrowsers(browser => {
+                browser.NavigateToUrl(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_SharedIdContent);
+
+                browser.First("h1"); // root master page
+                browser.First("h2"); // nested master page (shared ID)
+                var pageContent = browser.First("[data-ui='shared-id-page-content']");
+                AssertUI.InnerTextEquals(pageContent, "Shared ID Page Content");
+                // Default content from the shared ID placeholder should NOT be shown
+                browser.FindElements("[data-ui='default-shared-content']").ThrowIfDifferentCountThan(0);
+            });
+        }
+
+        [Fact]
+        [SampleReference(nameof(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_ContentWithDefault))]
+        public void Feature_LateContentPlaceHolders_DefaultContentUsedWhenNoContentProvided()
+        {
+            RunInAllBrowsers(browser => {
+                browser.NavigateToUrl(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_ContentWithDefault);
+
+                browser.First("h1"); // root master page
+                browser.First("h2"); // nested master page
+                // Default content from the NestedContent placeholder should be shown
+                var defaultContent = browser.First("[data-ui='default-nested-content']");
+                AssertUI.InnerTextEquals(defaultContent, "Default nested content");
+            });
+        }
+
+        [Fact]
+        [SampleReference(nameof(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_MismatchedContent))]
+        [Trait("Category", "dev-only")] // tests the error page behavior
+        public void Feature_LateContentPlaceHolders_MismatchedContent_ThrowsError()
+        {
+            RunInAllBrowsers(browser => {
+                browser.NavigateToUrl(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_MismatchedContent);
+                // The page should show an error because Content(NonExistentPlaceHolder) has no matching ContentPlaceHolder
+                AssertUI.InnerText(browser.First(".exceptionMessage"), s => s.Contains("NonExistentPlaceHolder"));
+            });
+        }
+
+        [Fact]
+        [SampleReference(nameof(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_RepeaterOneItem))]
+        public void Feature_LateContentPlaceHolders_ContentPlaceHolderInRepeater_OneItem_Works()
+        {
+            RunInAllBrowsers(browser => {
+                browser.NavigateToUrl(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_RepeaterOneItem);
+
+                browser.First("[data-ui='master-heading']"); // master page rendered
+                var items = browser.FindElements("[data-ui='repeater-item']");
+                Assert.Equal(1, items.Count);
+                AssertUI.InnerTextEquals(items[0], "Item 1");
+            });
+        }
+
+        [Fact]
+        [SampleReference(nameof(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_RepeaterZeroItems))]
+        [Trait("Category", "dev-only")] // tests the error page behavior
+        public void Feature_LateContentPlaceHolders_ContentPlaceHolderInRepeater_ZeroItems_ThrowsError()
+        {
+            RunInAllBrowsers(browser => {
+                browser.NavigateToUrl(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_RepeaterZeroItems);
+                // Should throw because ContentPlaceHolder is never instantiated (Repeater has no items)
+                AssertUI.InnerText(browser.First(".exceptionMessage"), s => s.Contains("RepeaterContent"));
+            });
+        }
+
+        [Fact]
+        [SampleReference(nameof(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_RepeaterMultipleItems))]
+        [Trait("Category", "dev-only")] // tests the error page behavior
+        public void Feature_LateContentPlaceHolders_ContentPlaceHolderInRepeater_MultipleItems_ThrowsError()
+        {
+            RunInAllBrowsers(browser => {
+                browser.NavigateToUrl(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_RepeaterMultipleItems);
+                // Should throw because ContentPlaceHolder is instantiated more than once (Repeater has 2+ items)
+                AssertUI.InnerText(browser.First(".exceptionMessage"), s => s.Contains("RepeaterContent") && s.Contains("already been resolved"));
+            });
+        }
+
+        [Fact]
+        [SampleReference(nameof(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_AuthViewContent))]
+        public void Feature_LateContentPlaceHolders_SameContentPlaceHolderIdInAuthenticatedViewTemplates_Works()
+        {
+            RunInAllBrowsers(browser => {
+                browser.NavigateToUrl(SamplesRouteUrls.FeatureSamples_LateContentPlaceHolders_AuthViewContent);
+
+                browser.First("[data-ui='master-heading']"); // master page rendered
+                // In unauthenticated state, the NotAuthenticatedTemplate is instantiated
+                var section = browser.First("[data-ui='not-authenticated-section']");
+                var content = section.First("[data-ui='auth-content']");
+                AssertUI.InnerText(content, s => s.Contains("Content from ContentPlaceHolder inside AuthenticatedView template"));
+            });
+        }
+
+        public LateContentPlaceHoldersTests(ITestOutputHelper output) : base(output)
+        {
+        }
+    }
+}
diff --git a/src/Samples/Tests/Tests/Feature/MasterPageTests.cs b/src/Samples/Tests/Tests/Feature/MasterPageTests.cs
index d1e9bf014b..6159fb5204 100644
--- a/src/Samples/Tests/Tests/Feature/MasterPageTests.cs
+++ b/src/Samples/Tests/Tests/Feature/MasterPageTests.cs
@@ -1,5 +1,6 @@
 using DotVVM.Samples.Tests.Base;
 using DotVVM.Testing.Abstractions;
+using Riganti.Selenium.Core;
 using Xunit;
 using Xunit.Abstractions;
 
diff --git a/src/Tests/Runtime/ConfigurationSerializationTests.cs b/src/Tests/Runtime/ConfigurationSerializationTests.cs
index 8433a2ea33..9408e8248f 100644
--- a/src/Tests/Runtime/ConfigurationSerializationTests.cs
+++ b/src/Tests/Runtime/ConfigurationSerializationTests.cs
@@ -39,6 +39,7 @@ void checkConfig(DotvvmConfiguration config, bool includeProperties = false, str
             serialized = serialized.Replace("System.Private.CoreLib, Version=***, Culture=neutral, PublicKeyToken=7cec85d7bea7798e", "CoreLibrary");
             serialized = serialized.Replace("mscorlib", "CoreLibrary");
             serialized = serialized.Replace("System.Private.CoreLib", "CoreLibrary");
+            serialized = serialized.Replace(", System.Core", "");
             // Special case - unify IServiceProvider
             serialized = serialized.Replace("System.IServiceProvider, CoreLibrary", "System.IServiceProvider, ComponentLibrary");
             serialized = serialized.Replace("System.IServiceProvider, System.ComponentModel, Version=***, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", "System.IServiceProvider, ComponentLibrary");
diff --git a/src/Tests/Runtime/config-tests/ConfigurationSerializationTests.SerializeDefaultConfig.json b/src/Tests/Runtime/config-tests/ConfigurationSerializationTests.SerializeDefaultConfig.json
index 5d893cd5ce..8463a4f3f9 100644
--- a/src/Tests/Runtime/config-tests/ConfigurationSerializationTests.SerializeDefaultConfig.json
+++ b/src/Tests/Runtime/config-tests/ConfigurationSerializationTests.SerializeDefaultConfig.json
@@ -1192,9 +1192,17 @@
         "type": "System.Int32",
         "defaultValue": -1
       },
+      "MasterPageChildPage": {
+        "type": "DotVVM.Framework.Controls.DotvvmControl, DotVVM.Framework",
+        "isValueInherited": true
+      },
       "PathFragment": {
         "type": "System.String"
       },
+      "PendingMasterPageCompositions": {
+        "type": "System.Collections.Generic.List`1[[DotVVM.Framework.Controls.PendingMasterPageComposition, DotVVM.Framework, Version=***, Culture=neutral, PublicKeyToken=23f3607db32275da]]",
+        "isValueInherited": true
+      },
       "ReferencedViewModuleInfo": {
         "type": "DotVVM.Framework.Binding.ViewModuleReferenceInfo, DotVVM.Framework"
       },
@@ -1202,6 +1210,10 @@
         "type": "DotVVM.Framework.Hosting.IDotvvmRequestContext, DotVVM.Framework",
         "isValueInherited": true
       },
+      "ResolvedMasterPageCompositionIds": {
+        "type": "System.Collections.Generic.HashSet`1[[System.String, CoreLibrary]]",
+        "isValueInherited": true
+      },
       "UniqueID": {
         "type": "System.String"
       },