From which version are you trying to upgrade the server to AMP 8.2.1? In AMP 8.2.x code, we have moved from /root/svn/mercury to /root/git/mercury directory.
During upgrade, it will be migrated to new directory, if server upgrade aborted then we have to look in to upgrade.log which we could find in /var/log/upgrade directory. please collect the log and open TAC ticket.
If server upgraded sucessfully, we could ignore this message.