Re: SEVERE: Dbcontrol Repository already exists. Fix the error(s) and run EM Configuration Assistant again in standalone mode.

Posted by ErmanArslansOracleBlog on Oct 03, 2017; 8:54am
URL: http://erman-arslan-s-oracle-forum.124.s1.nabble.com/SEVERE-Dbcontrol-Repository-already-exists-Fix-the-error-s-and-run-EM-Configuration-Assistant-again--tp3716p3719.html

You don't give any details about the action that you do. It seems, you want me to guess the environment details and the command used :)
I suspect the reason is-> The sysman repository or schema wasn't completely removed.

Check this note -> Creating Database Control Using emca Fails with Error: Dbcontrol Repository already exists (Doc ID 1593394.1)