I'm quite a newbee to being a System Admin so I'm asking help about this issue. So we have a Hybrid setup for our Exchange and Office365, now all users have been migrated to cloud and the old Exchange 2013 server is now turned off and is prepped for decomissioning. They asked me to create a new Exchange 2019 server for the whole purpose of management (since it is a hybrid setup) my problem is ,everytime I access ECP on the new exchange it throws an error "HTTP ERROR 500" - this keeps happening unless I turned on the old exchange 2013 server. So if I turned on the old exchange - I can login just fine but that is using the link "https://exch-mgmt/ecp/?ExchClientVer=15"
My question is, how do I get rid of the old server, and make sure I can just login right away using "Https://exch-mgmt/ecp" (this is my new Exch2019 server) and without turning on the old Exchange 2013.