Conversation history fails to open in VS Code panel across projects

Summary

The conversation history UI in the VS Code panel stops working — attempting to open past conversations does nothing. This affects multiple projects simultaneously, suggesting a shared extension state issue rather than a per-project problem.

Steps to reproduce

Exact trigger is unclear, but:

1. Use Claude Code in the VS Code panel across multiple projects
2. At some point, opening conversation history from the panel stops working
3. Affects all projects, not just the active one

Possibly related to the panel blank-out bug when dragging the panel to a separate window (see #28220), but this also occurs independently.

Expected behavior

Clicking on a past conversation in the history view should open and display that conversation.

Actual behavior

• History entries are visible but clicking them does nothing (or the panel remains blank)
• Affects all projects in the workspace simultaneously
• Only workaround is fully restarting VS Code, which is disruptive when the user has a complex workspace layout open

Environment

• VS Code: 1.109.5 (arm64)
• Claude Code extension: 2.1.52
• macOS: 15.7.3 (Sequoia)
• Hardware: MacBook Pro, Apple M2 Max, 96 GB RAM

Notes

User worked around this by switching to the terminal CLI for new sessions. Restarting VS Code resolves the issue but is not a practical workaround when multiple windows/tabs/terminals are arranged.