Anthropic reported this major-impact incident on its official status page on Sep 10, 2026, 15:54 UTC. It was resolved after 4d 3h.
Right now Anthropic is operational. Live Anthropic status →
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
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.
Overlapping incidents aren't necessarily related.
Anthropic reported 47 incidents in the last 90 days, 21 of them major or critical. A typical incident lasted 1h 4m. See Anthropic's uptime and incident history