[BUG] [CRITICAL] Cowork Dispatch responses never render in desktop UI — backend processes successfully but TypeError crashes renderer

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?

aDispatch in Cowork mode is completely non-functional on the desktop UI. Messages sent via dispatch are received and processed successfully by the backend (bridge + local session), and responses are generated and delivered back to the API without errors. However, no responses ever render in the desktop dispatch tab.

The dispatch conversation renderer crashes on every render cycle with:

Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'includes')

followed by:

[REACT_QUERY_CLIENT] QueryClient error: Error: Not found

This makes Dispatch completely unusable despite the backend working perfectly. The issue persists through:

• Full app restart
• - Windows reboot
• - - Complete wipe of IndexedDB, Local Storage, Session Storage
• - - - Clearing all Chromium caches (Cache_Data, GPUCache, Code Cache, DawnGraphiteCache)
• - - - - Resetting bridge-state.json (fresh session creation)

The bug is in the app's shipped JavaScript code, not in stored data.

Root Cause Analysis (from main.log)

The transport metadata reports dispatch_agent_name: null:

[transport:ccr] reportMetadata {"permission_mode":"default","dispatch_agent_name":null}

The UI code likely calls .includes() on this null value without a null check, crashing the renderer. This crash prevents the QueryClient from loading conversation data (hence "Not found"), which means responses never display.

Evidence: Backend Works Perfectly

From main.log, every message completes successfully:

[sessions-bridge] Received user message for session cse_01AGE721y9HgiaUm2nbT3fLA: "Another test"
[transport:ccr] reportDelivery event_id=533b57e5... status=processing
[transport:ccr] reportState idle -> running
[Result] Turn succeeded for session local_ditto_841513b9...
[transport:ccr] reportDelivery event_id=533b57e5... status=processed
[transport:ccr] reportState running -> idle
[sessions-bridge] Query completed for session cse_01AGE721y9HgiaUm2nbT3fLA (pendingTurns=0, isError=false)

The audit.jsonl confirms responses are generated:

• "Hello" -> "Hey Tamer! What can I help you with today?"
• - "Testing" -> "Looks like we're all systems go!"
• - - "testing again" -> "Still here, still ready!"

All responses exist in the audit log but never render in the UI.

Related Issue

This may be related to #36157 (Dispatch causes black screen freeze), which also reports TypeError: Cannot read properties of undefined (reading 'includes') and rapid re-rendering loops. However, in this case there is no black screen freeze -- the app runs fine, dispatch just silently fails to show responses.

What Should Happen?

When a task is sent via Dispatch (mobile or API), and the backend successfully processes it and generates a response, that response should render in the Dispatch tab of the desktop Cowork UI. The user should see the assistant's reply appear in the dispatch conversation thread, just as it did in previous versions. No TypeError or QueryClient errors should occur in the renderer.

Error Messages/Logs

aFrom claude.ai-web.log (repeats on every dispatch interaction):

2026-03-28 00:04:57 [error] Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'includes')
2026-03-28 00:04:57 [error] [REACT_QUERY_CLIENT] QueryClient error: Error: Not found
2026-03-28 00:05:09 [error] Uncaught (in promise) TypeError: Cannot read properties of undefined (reading 'includes')

From main.log (initial session spawn failure, recovered on retry):

2026-03-27 23:37:52 [error] Process spawn error for session local_ditto_841513b9:
  RPC error -1: failed to mount .../skills as .claude/skills: failed to chown mount point:
  chown /sessions/awesome-hopeful-ritchie/mnt/.claude/skills: no such file or directory
  unhealthy_reason: 'initialization_failed'

Transport metadata showing null agent name (suspected crash trigger):

[transport:ccr] reportMetadata {"permission_mode":"default","dispatch_agent_name":null}

Steps to Reproduce

a1. Open Claude Desktop (v1.1.7714+) on Windows 11 with Cowork enabled

1. Enable Dispatch in Cowork settings (already consented)
2. 3. Send any message via Dispatch (from mobile app or desktop dispatch tab)
3. 4. Observe: the message appears in the dispatch tab, the desktop processes it successfully (visible in main.log), a response is generated and stored in audit.jsonl
4. 5. Bug: The response never renders in the dispatch conversation UI on desktop
5. 6. Check claude.ai-web.log: TypeError: Cannot read properties of undefined (reading 'includes') fires on every dispatch interaction

Exhaustive remediation attempted (none fixed it):

• Restarting Claude Desktop app
• - Rebooting Windows entirely
• - - Resetting bridge-state.json (forces fresh dispatch session creation)
• - - - Wiping IndexedDB, Local Storage, Session Storage
• - - - - Deleting all Chromium caches (Cache_Data, GPUCache, Code Cache, DawnGraphiteCache, DawnWebGPUCache)
• - - - - - Full data wipe except local-agent-mode-sessions

None of the above resolved the issue because the bug is in the compiled app JavaScript, not in stored data.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.1.7714 (Claude Desktop / Cowork mode, Electron 40.4.1, Chrome 144.0.7559.173)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

System Information

• App: Claude Desktop 1.1.7714 (Microsoft Store / MSIX package)
• - Electron: 40.4.1 / Chrome 144.0.7559.173 / Node 24.13.0
• - - OS: Windows 11 Home (10.0.26200)
• - - - CPU: AMD Ryzen 7 9800X3D (16 cores)
• - - - - RAM: 31.65 GB (41.9% used)
• - - - - - Terminal/Shell: N/A — this is Cowork Dispatch, not CLI
• - - - - - - Platform: Claude Desktop (Cowork mode), not API

Impact

Dispatch is a core Cowork feature allowing remote task assignment. This bug renders it completely unusable — the entire response pipeline works but responses are invisible to the user. This defeats the purpose of Dispatch entirely.

Suggested Fix

The TypeError: Cannot read properties of undefined (reading 'includes') strongly suggests a missing null check. The transport metadata shows dispatch_agent_name: null. If the UI code does dispatch_agent_name.includes(...) without guarding for null/undefined, it would produce exactly this crash pattern. A simple dispatch_agent_name?.includes(...) or (dispatch_agent_name || '').includes(...) would likely fix it.

Relationship to #36157

Issue #36157 reports the same TypeError and includes crash but with a black screen freeze. This report describes a distinct symptom (no freeze, just silent response rendering failure) on a different platform (Windows vs macOS). Both likely share the same root cause.