Degraded functionality for Claude Cowork on Windows
Sep 10, 15:54 UTCSep 14, 19:14 UTC
Duration
4d 3h
Impact
Major
Root cause
Not disclosed
Anthropic, 90 days
94 incidents
Affected
Claude Cowork
Final update
This issue has been resolved. Microsoft has released a September 14 Windows update that fixes it: https://support.microsoft.com/en-us/servicing/os/windows-11/2026/09/kb5129195-windows-11-24h2-25h2-security-update
Timeline
- Resolved · Sep 14, 19:14 UTC
This issue has been resolved. Microsoft has released a September 14 Windows update that fixes it: https://support.microsoft.com/en-us/servicing/os/windows-11/2026/09/kb5129195-windows-11-24h2-25h2-security-update
- Identified · Sep 10, 15:54 UTC
A Windows update released September 8 has left Claude Cowork on Windows unable to run local commands, because its workspace can no longer reach your computer's drive. For most users, chat and file reading and editing still work. There's no in-app workaround yet, and restarting or reinstalling won't help. Microsoft has developed a fix and is working to release it. We'll post an update when we have more to share.
More from Anthropic
Full history| Started | Incident | Impact | Duration |
|---|---|---|---|
| Sep 2200:57 UTC | Elevated errors for multiple models | major | 1h 38m |
| Sep 1616:18 UTC | Issues with Google Play subscriptions | none | 33m |
| Sep 1509:48 UTC | Intermittent error spikes for Claude Mythos 5.1 and Claude Fable 5.1 | major | 1h 26m |
| Sep 1114:19 UTC | Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1 | major | 17m |
| Sep 1021:43 UTC | Elevated latency on the Claude API for some users | minor | 1h 41m |
| Sep 313:26 UTC | Elevated errors for multiple models | major | 2h 57m |
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