Hi Mirela_Buru ,
Yes - the log I extracted from was the session that produced the screen grab I included in my previous post. During the work I was doing to try and fix this and rerun the HCW after making adjustments, the migration endpoint error was produced every time.
Just before this last run, I found the adminCount attribute of the Exchange server computer account was set to 1, where it should be set to 0. This server was previously a member of a DAG and a few other high availability options, before changing tack and running a single on-prem Exchange server as a VM on a high availability failover cluster. I checked server account memberships and other suggestions, but was satisfied that it just remained to set that value to 0, reboot the server, and try the HCW again, which I did, but with no change.
I am more than happy to provide after hours remote access for your troubleshooting, or send you the entire contents of the %appdata%\Microsoft\Exchange Hybrid Configuration folder which dates back to 23 March. Please send me a DM if there is anything I can assist with offline from this blog.
Kevin