Incident report · read from Anthropic's status page
Anthropic incident: Degraded functionality for Claude Cowork on Windows
Resolved after 4 d 3 h (10 Sep 2026 15:54 – 14 Sep 2026 19:14 UTC), impact major, affecting Claude Cowork.
Timeline
- identified
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.
- resolved
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
Affected components
- Claude Cowork: degraded for 4 d 3 h
What the crowd did
- 1 136 clicks, 40 zombies at their worst, 3769 breaches, over 3 d 4 h — the siege in full
That is this site's own record of the crowd at Anthropic's gate, not anything Anthropic published.
Source
Anthropic's own report of this incident, on Anthropic's status page. This page is a record of Anthropic's own report; where the two disagree, theirs is right.
Last checked .
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