In place upgrade completed 5/17/2021 no problems at all ran until 6/24 and then rebooted server and server did not come back up.
Similar thing happened on 8/2/2021 but was logged in and stopped and started Application on server. Server stopped responding tried to log off then tried to log back on and couldn't log back on. Connected via command prompt and restarted server which worked. Minimal services started. Could not connect to server via remote desktop or VM console. The VM console is just black. does not respond to ctl alt del. After 20 minutes I can finally connect to server via Computer management app and can see minimal service started. Let run 12 hours and nothing starts not able to log in not able to do anything. It like the operating system is corrupt all of a sudden. This is a Email archive server and has 1.91 TB of data and takes roughly 13 hours to restore from Backup. The question I have has this happened to anyone? Is there a way to reload the operating system again to 2019 since it already is on 2019. This server was created on 2012 R2 and has been functioning sine 2017 without any OS issues. I have never seen this happen before. Any help would be much appreciated.