[BUG] Claude Cowork stuck on 'sending request'

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Cowork gets permanently stuck on "sending request" after the Statsig client encounters network connectivity issues. Even after network is restored, the Statsig client remains in a broken state and cannot recover without manually clearing app cache.

Key symptoms:

• Regular Claude chat works fine
• Cowork specifically stuck on "sending request"
• Network connections are established but requests hang

Environment

• Platform: macOS (Tahoe)
• Claude Desktop Version: Latest (January 2026)
• Subscription: Claude Max

Root Cause Analysis

From ~/Library/Logs/Claude/claude.ai-web.log:

WARN  [Statsig] useFeatureGate hook failed to find a valid StatsigClient for gate 'asset_prefetch_enabled'.
ERROR [Statsig] Failed to parse EvaluationResponse
ERROR [REACT_QUERY_CLIENT] QueryClient error: Error: Invalid authorization

The Statsig client (feature flag system) gets into a corrupted state when statsig.anthropic.com is temporarily unreachable. Once corrupted, the client cannot recover even after connectivity is restored.

Steps to Reproduce

1. Use Claude Desktop with a VPN that blocks or interferes with statsig.anthropic.com (e.g., Mullvad VPN via Tailscale exit node)
2. Attempt to use Cowork - it will fail/hang
3. Fix network connectivity (disable VPN or add split tunnel routes)
4. Attempt Cowork again - still stuck on "sending request"
5. Regular chat continues to work fine

Expected Behavior

• Statsig client should gracefully handle network failures
• Statsig client should automatically retry/recover when network is restored
• Cowork should not permanently break due to transient network issues

Actual Behavior

• Statsig client fails to parse response and enters permanent error state
• Cached state becomes corrupted
• Only fix is to manually delete cache directories:
• ~/Library/HTTPStorages/com.anthropic.claudefordesktop/
• ~/Library/Caches/com.anthropic.claudefordesktop/

Suggested Fix

1. Add retry logic with exponential backoff to Statsig client initialization
2. Implement cache invalidation when Statsig responses fail to parse
3. Add a "reset" or "clear cache" option in the app UI for users
4. Consider graceful degradation - allow Cowork to function with cached/default feature flags if Statsig is unreachable

Workaround

Clear the cache directories and restart the app:

rm -rf ~/Library/HTTPStorages/com.anthropic.claudefordesktop/
rm -rf ~/Library/Caches/com.anthropic.claudefordesktop/

Then relaunch Claude Desktop.