The disruption of the Exchange service has been resolved since about 8 am. The cause of the disruption was a bug in the patch provided by Microsoft for the domain controllers. More information can be found at: https://borncity.com/win/2022/01/12/patchday-windows-8-1-server-2012-r2-updates-11-januar-2022-mgliche-boot-probleme/?fbclid=IwAR10HLYwktXVJ83eCOiGATPmrwc7o09cUPSOMEhw1L-1PBEr3NajkZYtaEE
