If you are having problems with Windows Server 2012 Domain Controllers reboot looping, Microsoft just released a new security update (Jan 11th 2022) that causes those problems.

Here are the steps to uninstall the update:

  1. Start your VM in safe mode
  2. Uninstall Update Rollup KB5009624
  3. Reboot your server
  4. (optional) Check if critical services are up and running
  5. For the moment disable automatic installation of updates until Microsoft releases a fix