/resume fails after CLI restart on Windows when session event contains raw U+2028

[jongalloway]

Summary

After restarting GitHub Copilot CLI on Windows, I was unable to resume the previous session because the saved session file appears to be corrupted.

Environment

• GitHub Copilot CLI: 1.0.24
• OS: Windows
• Shell: PowerShell

Repro steps

1. Start a Copilot CLI session in a local repository.
2. Do some work in the session.
3. Restart the CLI.
4. Try to resume the prior session using /resume.

Expected

The previous session should be available and resume successfully with its saved context.

Actual

Resume fails and reports that the session file is corrupted.

Error shown by the CLI

Failed to resume session: Error: Session file is corrupted (line 9316: SyntaxError: Unterminated string in JSON at position 2716 (line 1 column 2717))

Additional context from local inspection

The process log reported that resume failed while parsing:

• session a44946c9-5579-44a6-8a75-87fb6d680bf3
• file ...\\.copilot\\session-state\\a44946c9-5579-44a6-8a75-87fb6d680bf3\\events.jsonl
• event line 9316
• event type hook.start

I inspected that record locally and found a raw Unicode line-separator character U+2028 at the reported parse position (2716).

Relevant excerpt from the record:

... ![](/static/assets/effectsvector.50f5035.svg)\n\n## Effects that polish,<U+2028>transform, or break the rules\n\nWith a full suite of effects, FL Studio lets you refine ...

The events.jsonl file had about 13,351 lines, and this appears to be the only U+2028 / U+2029 separator found in the failing record.

Notes

• I hit this while troubleshooting MCP reload behavior for a local project, but the resume failure itself seems like a standalone CLI issue.
• I was not able to recover the previous session through resume.