I just upgraded from 10380 to 10455, removed the Git plugin from .BuildServer/plugins and now have the problem, that the server hangs when 'checking for changes'.
I have looked at the VCS settings, they are identical. I use ssh with default key functionality. When I try to "test connection" in the VCS setup dialog, I get the same hang.
I have enabled the debug logs in teamcity-server-log4j.xml but see nothing related to the operation in the logs.