If the policy server is not able to write events to the pmevents.db database for any reason, it will queue the event to the queue directory.
You can check if the event is already in the database by running the following command:
/opt/quest/sbin/pmlog --uniqueid <UID mentioned in message>
E.g
/opt/quest/sbin/pmlog --uniqueid 93edd453ef7c2bf4e4486a2d75b26d088a356f4a
If the pmlog command fully shows the event then it has already been processed, however the queue files were not properly removed from the event queue directory.
In this case the files with that uniqueid in the event queue directory can be safely removed.
The event queue directory is at the following location:
/var/opt/quest/qpm4u/evcache/events