Windows 11 shutdown bug forces Microsoft into damage control

"The emergency fix, KB5077797, landed on January 17 for Windows 11 version 23H2 and is aimed squarely at cleaning up the mess left behind by the regular monthly update earlier in the month. That update, intended to close a long list of security holes, instead left some systems stubbornly refusing to shut down, restart, or hibernate, with shutdown commands frequently shrugged off by the operating system."

"The culprit turned out to be System Guard Secure Launch, one of Microsoft's boot-time hardening features, which didn't play nicely with the January update. On affected systems - typically builds where Secure Launch is enabled by default - machines would go through the motions of shutting down, then either sit there humming away or spring back to life. That translated into laptops quietly draining overnight and desktops burning power long after everyone had gone home."

"The OOB update also rolls out fixes for a separate but no less annoying authentication problem. Some users found themselves unable to sign in over Remote Desktop after installing the January patches, thanks to credential prompts that failed or looped endlessly. That bug affected both client and server environments and added to the sense that January's updates were doing more harm than good in some scenarios."

An out-of-band Windows 11 update, KB5077797, restores normal shutdown, restart, and hibernation behavior after January's cumulative update caused systems to ignore shutdown commands. The failure was linked to System Guard Secure Launch interacting badly with the January update on builds where Secure Launch is enabled by default. Affected machines appeared to shut down but either stayed running or sprang back to life, causing laptop battery drain and unnecessary desktop power use. The emergency update also fixes Remote Desktop sign-in credential prompt failures and loops. Microsoft confirmed the bug was introduced by January's cumulative update and released the unscheduled fix. A separate Outlook POP profile hang remains unpatched.

Read at Theregister