[BUG] Cowork shows "Not logged in · Please run /login" — persists across v1.3561.0 to v1.3883.0

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?

Cowork mode in Claude Desktop shows "Not logged in · Please run /login" on every message sent. Chat mode and Code mode work fine without any issues. The error appears immediately after sending any message in Cowork, regardless of the content. This has persisted across multiple app versions (v1.3561.0 through v1.3883.0) and survives a complete fresh uninstall/reinstall.

The error is consistent and reproducible — there is no workaround. The error message itself suggests running /login, but Cowork does not accept slash commands, making the error message unhelpful.

What Should Happen?

Cowork should accept the user's message and execute it without authentication errors. Prior to 4/20/2026 midday, Cowork was functioning normally.

Error Messages/Logs

From main.log (Claude Desktop):
2026/04/21 13:48:25 [Result] Turn failed for session [REDACTED]: subtype=success, is_error=true
2026/04/21 13:48:25 [CycleHealth] Unhealthy cycle: {
  cycle_health: 'unhealthy',
  had_first_response: true,
  unhealthy_reason: 'api_error',
  error_message: 'Not logged in · Please run /login',
  is_resume: true
}

From cowork_vm_node.log (VM startup — healthy):
[info] [VM:start] Startup complete, total time: 8500ms
[info] [postConnect] Installing SDK: version=2.1.111
[info] [VM] API reachability: REACHABLE

From coworkd daemon log (VM infrastructure — healthy):
[coworkd] checking reachability https://api.anthropic.com/ (timeout=30s)
[coworkd] reachability check passed (status=404)
[coworkd] connected, waiting for commands
[coworkd] SDK binary v2.1.111 already installed, skipping

UI Error Message:
Not logged in · Please run /login

Steps to Reproduce

1. Open Claude Desktop (v1.3883.0 or later)
2. Log in to your account (Chat and Code modes confirm successful login)
3. Switch to Cowork mode (visible in the mode switcher)
4. Type any message (e.g., "hello")
5. Send the message
6. Expected: Cowork executes the message
7. Actual: Error appears: "Not logged in · Please run /login"

Reproducibility: 100% — happens on every message in Cowork mode

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

v1.3561.0 (worked up to 4/20/2026 midday)

Claude Code Version

Claude Desktop v1.3883.0 (93ff6c) 2026-04-21T17:24:01.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Troubleshooting Already Completed:

• Logout/login cycle
• Close and reopen app
• Full uninstall and fresh reinstall from website
• Computer restart
• Clear browser cache and cookies
• Delete VM bundles directory
• Delete local session data (local-agent-mode-sessions, claude-code-vm)
• Verified environment variables empty
• Confirmed CoworkVMService running
• Update to latest version v1.3883.0

What Works:

• Chat mode: Functions normally without errors
• Code mode: Functions normally without errors
• Cowork VM infrastructure: Boots successfully, connects to network, reaches api.anthropic.com
• Account login: User is logged in correctly (Chat/Code functional)

What's Broken:

• Cowork authentication: API rejects every message with api_error: 'Not logged in'
• Root cause: The VM is healthy and reachable, but the credential pipeline from Claude Desktop to the VM is broken

Key Insight:
The error originates after the VM successfully connects — when Claude Desktop attempts to pass authentication credentials into the Cowork VM. The is_resume: true flag in the error log suggests the VM is trying to resume a cached session that may be invalid or revoked on the server side.

Environment Details:

• OS: Windows 11
• Plan: Claude Max
• Network: No VPN, no proxy, no firewall blocks
• No subscription changes between working and broken state

Hypothesis:
This appears to be either:

1. A server-side regression in Cowork's OAuth client or credential handling
2. An account-level credential issue where Cowork's auth token is broken/revoked but Chat/Code tokens are valid
3. A session resumption bug where the VM cannot validate its cached session token with the server

The fact that Chat and Code modes work fine, while Cowork fails specifically and consistently, suggests the issue is in Cowork's separate authentication pipeline, not the user's account or local Claude Desktop state.