Microsoft is investigating widespread problems caused by a recent mandatory Windows 11 update, which has been linked to game crashes, login errors, display glitches and system crashes on some PCs. The KB5121003 patch, released on 11 August as the month's major security update, fixed over 400 vulnerabilities but appears to have introduced significant new bugs, causing particular disruption for gamers.

The gaming community has reported a surge in unexpected crashes since installing the update, with Embark Games' titles ARC Raiders and The Finals especially affected due to an apparent driver compatibility issue. Embark is developing a fix but has given no timeframe, and in the meantime advises users to disable the affected driver via Command Prompt. Users can also remove the patch entirely through Update History settings, though doing so would leave systems exposed to the hundreds of vulnerabilities it patched. Microsoft has acknowledged the issue and opened an investigation, but has yet to announce a fix, and is asking affected users to report problems via the Feedback Hub.