Windows September update breaks Claude Cowork sandbox; uninstalling the patch is the only fix

Anthropic confirmed a September 8 Windows update broke Claude Cowork's ability to run local commands; users traced it to cumulative update KB5124008, and uninstalling the patch is currently the only fix.

2026-09-10 ~ 2026-09-10 · 2 related posts

• Windows update KB5124008 breaks Anthropic Cowork's sandbox shell; uninstall is the only fix — standard_deviant_Q · 2026-09-10
• Windows Update Breaks Claude Cowork's Local Command Execution; Microsoft Fix Incoming — ClaudeAI-mod-bot · 2026-09-10