I recently went through and removed a whole bunch of non-essential plugins.
Since then each day I open Jenkins to a new "Manage Old Data" message which are these CannotResolveClassExceptions against every freestyleJob. I discard it, they go away, and it's back the next day.
I have Job DSL which generates those jobs, and the jobs are scheduled to run each morning, but there's really nothing special in them. If I run them manually it doesn't generate the message.
Would anyone have a clue what might be causing it? I'm on Jenkins 2.37.