Degraded functionality for Claude Cowork on Windows

What to do

• Check whether you use Anthropic Claude Cowork in us. Check your stack

  Paste a package.json, lockfile, Terraform or a list of domains at down.guide/stack to see every provider you depend on.

• Confirm your retries, queues and scheduled jobs caught up after the 4d 3h it lasted.

  Anything that failed between 2026-09-10 15:54 UTC and 2026-09-14 19:14 UTC may need a replay.

• Subscribe to Anthropic's feed to hear about the next one first. RSS feed

  https://down.guide/feed?provider=anthropic works in Slack (/feed subscribe), Discord feed bots and any RSS reader.

Updates from Anthropic 2

1. identifiedSep 10, 2026, 3:54 PM 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.

   provider

2. resolvedSep 14, 2026, 7:14 PM 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

   provider

Corrections

None so far.

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