Anthropic incident

Degraded functionality for Claude Cowork on Windows

Major Resolved View vendor source →

Anthropic experienced a major incident on September 10, 2026 affecting Claude Cowork, lasting 4d 3h. The incident has been resolved; the full update timeline is below.

Started
Sep 10, 2026, 03:54 PM UTC
Resolved
Sep 14, 2026, 07:14 PM UTC
Duration
4d 3h
Detected by Pingoru
Sep 10, 2026, 03:54 PM UTC

Affected components

Claude Cowork

Update timeline

  1. identified Sep 10, 2026, 03:54 PM UTC

    A Windows update released September 8 has caused Claude Cowork on Windows is unable to run local commands on your PC, because its workspace can no longer reach your computer’s drive. For most users, chat and reading or editing files still work. We have identified the cause as a change in Windows; Microsoft has developed a fix and is working on releasing it. There’s no in-app workaround yet, and restarting or reinstalling won’t help. We’ll post an update when we have more to share.

  2. resolved Sep 14, 2026, 07:14 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