Just to update you folks, after a session with TAC (Debug) yesterday:
There is a component called SIDupdater nowadays which has the job to update all ad_user and ad_group objects with SID values, if they are empty. This component runs after upgrade to R81+. If it fails for whatever reason, it retries later three more times. After that, it gives up. You can see this in db table SidUpdaterRetriesCounter_data.
In our case, this job ran, but without success. We modified that table to reset the retry-counter and did a cprestart. Before that, we enabled debug logs for cpm->SIDupdater to see, what it is doing.
SIDupdater ran, found all affected ad_user and ad_group objects, aquired SIDs for them successfully but finally crashed with a NullPointerException before being able to push the updates to db.
R&D will now look at debug logs to understand, why it crashes.
I will update you again, when this issue is solved.
Thanks, Val, for routing that TAC case in the right direction 🙂