Error on qickfind

Hello,

after an upgrade to 2018R3 not all persones are indexed by quickfind.

I've tried this solution: http://help.sagecrm.com/on_premise/en/2017R2/troubleshooting/Content/Troubleshooting/TS_RecreatingQuickFindIndex.htm

But with the same result.

In the logs i found this error.

ERROR [taskScheduler-1]: 29-Nov-2018 12:30:52.293 Creating core: sagecrmj failed. Exception was: com.sage.crm.fulltextsearch.exception.IndexingException: Core with given name already exists!

Can someone give me a hint what to do?

Hope to get help soon.

Tom