Just a quick post; the latest Windows Server updates for 2012R2, 2019 and 2022 (haven’t seen 2016) can cause ReFS issues. After the installation, ReFS volumes are shown as RAW and are no longer accessible; so if you’re using ReFS for your repositories, then take be aware of this when installating the update. Besides that, those updates can also cause bootloops for domain controllers and break Hyper-V.

Depending on your Windows Server version one of the following updates could have caused the issue: KB5009624, KB5009557, KB5009555

If you’re affected then removing the mentioned update should solve the issue. Don’t (!) try to repair the ReFS volume, because this could cause a dataloss.

This should remind everyone why 3-2-1 for Backups is so important.

Further information:

https://www.bleepingcomputer.com/news/microsoft/new-windows-server-updates-cause-dc-boot-loops-break-hyper-v/

https://forums.veeam.com/veeam-backup-replication-f2/beware-possible-raw-refs-volumes-after-installing-january-updates-t78634.html

Update #1:

Microsoft has pulled the updates, thanks @Mildur 

https://www.bleepingcomputer.com/news/microsoft/microsoft-pulls-new-windows-server-updates-due-to-critical-bugs/amp/

Update #2:

Microsoft has released the updates again and it looks like they didn't fix them. (Thanks @MicoolPaul )

https://www.bleepingcomputer.com/news/microsoft/microsoft-resumes-rollout-of-january-windows-server-updates/

Update #3:

Microsoft has released an out-of-band update, which can possibly resolve the issues:

https://www.bleepingcomputer.com/news/microsoft/microsoft-releases-emergency-fixes-for-windows-server-vpn-bugs/