[BUG] VS Code extension webview goes blank after auto-update during active session - stale resource references

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When the Claude Code VS Code extension auto-updates while a conversation is active, the webview goes completely blank/black. The extension continues running in the background (CLI process active, file changes being made) but the UI is completely unresponsive and shows no content.

The root cause is that the webview retains cached references to resources (e.g., claude-logo.svg) in the old extension folder, which no longer exists after the update.

What Should Happen?

1. Auto-update should defer until active sessions are closed, OR
2. Extension should gracefully reload webview with updated resource paths, OR
3. User should see "Extension updated, please reload" prompt instead of blank screen

Error Messages/Logs

Failed to load resource: net::ERR_FILE_NOT_FOUND
vscode-file://vscode-app/c:/Users/[user]/.vscode/extensions/anthropic.claude-code-2.0.45-win32-x64/resources/claude-logo.svg
vscode-file://vscode-app/c:/Users/[user]/.vscode/extensions/anthropic.claude-code-2.0.50-win32-x64/resources/claude-logo.svg

MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 exit listeners added to [process].
AbstractContextKeyService has been disposed
Could not create web worker(s). Falling back to loading web worker code in main thread, which might cause UI freezes.

Steps to Reproduce

1. Open Claude Code in VS Code and start a conversation
2. Allow the extension to auto-update (updates happen automatically in background)
3. Continue using the session after update completes
4. Webview goes blank - either immediately or after the next permission prompt
5. Open DevTools Console (Ctrl+Shift+P → "Developer: Open Webview Developer Tools")
6. Console shows ERR_FILE_NOT_FOUND for old extension version paths like anthropic.claude-code-2.0.45-win32-x64

Claude Model

Sonnet

Is this a regression?

I don't know

Last Working Version

N/A

Claude Code Version

2.0.58

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code

Additional Information

Root cause identified: Multiple old extension versions remain on disk after updates:

• anthropic.claude-code-2.0.45-win32-x64
• anthropic.claude-code-2.0.50-win32-x64
• anthropic.claude-code-2.0.55-win32-x64
• anthropic.claude-code-2.0.56-win32-x64
• anthropic.claude-code-2.0.57-win32-x64

The webview caches paths to these old versions and doesn't refresh when extension updates. When it tries to load claude-logo.svg from deleted paths, the webview fails to render.

Workaround:

1. Close VS Code
2. Delete old extension folders from ~/.vscode/extensions/
3. Clear VS Code cache (%APPDATA%/Code/Cache, %APPDATA%/Code/CachedData)
4. Restart VS Code

Suggested fixes:

1. Clean up old extension versions during update process
2. Implement webview resource path refresh after extension update
3. Add version mismatch detection to show reload prompt instead of failing silently

Related Issues: #8434, #11178, #10481, #2230