[BUG] On VS Code 1.105.1: Claude panel empty + Extension host crashes (chatParticipant… + OOM)

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?

On VS Code 1.105.1 (Stable) with Claude Code v2.0.35, the Claude panel opens but stays empty. Shortly after, the extension host crashes and restarts in a loop. Console shows:

ERR chatParticipant must be declared in package.json: claude-code

JavaScript heap out of memory → Extension host terminated unexpectedly

This makes Claude Code unusable.

It was working correctly and another text echange with claude code was not working

What Should Happen?

The Claude chat UI should render normally and be interactive (able to start a new chat, reply, etc.), without crashing the extension host.

Error Messages/Logs

Webview DevTools Console

log.ts:460   ERR chatParticipant must be declared in package.json: claude-code
localProcessExtensionHost.ts:281 ... JavaScript heap out of memory
abstractExtensionService.ts:843 Extension host (LocalProcess pid: 5132) terminated unexpectedly

Output → Claude Code (extraits)

Claude code extension is now active?
MCP Server running on port ...
OAuth tokens found in secure storage
Auth status: method=claudeai
...
[ERROR] "AbortError: The operation was aborted. at <anonymous> (B:/~BUN/root/claude.exe:4049:10596)"
[ERROR] Failed to save config with lock: Error: Lock file is already being held

Status bar
“The extension host terminated unexpectedly. Restarting…”

Steps to Reproduce

Open VS Code 1.105.1 on Windows and a workspace.

Open the Claude Code sidebar or run Claude: Start New Chat.

Observe that the panel is blank.

Within seconds, VS Code shows “The extension host terminated unexpectedly. Restarting…” and repeats.

Open Webview Developer Tools → Console to see chatParticipant… error; see OOM in Log (Window) and Extension Host logs.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

(2.0.35 broken; 2.0.34 also broken for me)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

Reload Window, full restart.

Disable/Enable + reinstall Claude Code.

Roll back to 2.0.34 (same result).

Clear Webview cache: %APPDATA%\Code\Cache, CachedData, Service Worker\CacheStorage.

Disable hardware acceleration via argv.json ("disable-hardware-acceleration": true).

Kill claude.exe; remove locks C:\Users\<me>\.claude\ide\*.lock.

Temporary profile with minimal extensions → still repro.

Disable GitHub Copilot and Copilot Chat, clear their cache; increase extension host memory in argv.json: