we upgraded the agents from 22.214.171.124 to 126.96.36.199 - worked fine.
Now we want to delete the old agent as described in the documentation (http://docs.oracle.com/cd/E24628_01/upgrade.121/e22625/upgrading_12101_PS1_agents.htm#autoId11) under "Freeing the Disk Space Occupied by the Old Management Agent".
After freeing the space and resyncing the agent with EM12cR2 the agent ist blocked with the following error message:
"Plugin mismatches between agent and repository. Check plugin:[ The plug-in is oracle.sysman.db Version in pla inventory : 188.8.131.52.0 Version on agent : null Content type : AGENT Error code : TARGETS_BEING_MONITORED Error Msg : Ziele werden aktiv von diesem Plug-in überwacht. Deshalb ist ein Upgrade/Downgrade/Löschen nicht möglich, The plug-in is oracle.sysman.db Version in pla inventory : 184.108.40.206.0 Version on agent : null Content type : AGENT Error code : NOT_FOUND_IN_INPUT Error Msg : Dieses Plug-in ist im Bestand für den angegebenen Agent vorhanden, wurde jedoch in der Eingabe nicht angegeben]"
Approx. 15 min later the agent is unblocked and everything seems to be ok. But, if we are resyncing again the same error message is displayed and we have to wait again approx. 15 min.
Our question: How to correct the mismatches to avoid the above error message?
This sounds like the same problem I had (EM12cR2 - how to clean up old agent core directories after upgrade? If I removed the old 220.127.116.11.0 directory, my agents would get blocked with a plugin mismatch message like you received. I think you may have removed the entire core/18.104.22.168.0 directory rather than only removing the contents and leaving behind the empty directory.
Inside the core/ directory, just create a new directory named "22.214.171.124.0". It does not need to contain anything. Once that directory is created, your agents should hopefully no longer get blocked. If they still get blocked you may have a different problem.
You should not be getting plugin mismatch error. Log an SR and upload the agent instance home logs , we have to look at your environment. Send me the SR number.
Why are you running resync command ? Its not required to run resyn command ever time you touch your agent.