Microsoft released the KB5009566 update for Win11 and the KB5009543 update for Win10 around January 15. In addition, it also pushed similar updates for multiple versions of Windows Server and fixed the bug of text display. However, this batch of updates in January 2022 caused serious failures in the Windows system and even affected the normal operation of the server.
If the user chooses the L2TP method to connect to the VPN, there will be a failure. In addition, there is a bug where the domain controller restarts unexpectedly. For server users, the impact of Windows Server failures is even more serious. IT operations personnel found that after installing the KB5009555 update, Windows Server 2012 experienced a looping restart and the VPN client was malfunctioning.
Also, hard drives with the ReFS file system become inaccessible and appear in RAW format on the system. The Verge interviewed a university IT administrator who said he had to roll back the update pushed last Tuesday because it made the ReFS hard drive unusable. In order to ensure data security, these hard drives have to be backed up.
Microsoft has announced the rollout of an OOB out-of-band update to fix these issues. Users can find it in optional updates or manually download and install it. The following are the updated version numbers for different systems: