I would like to know if anybode else had this issue.
We upgraded our UF on AIX to 8.1.3 from 8.0.4, following the guidelines from Splunk.
We have set outputs.conf to use indexer discovery.
After the upgrade we saw these message:
The pass4SymmKey has not changed during the upgrade.
We changed the configuration to bypass indexer discovery, and that got data flowing into the system again.
Yes, I did try to update the pass4SymmKey, that didn't work.
It seems this problem is only on the AIX part, we have succesfully upgraded both Linux and Windows so it is not a general bug.