PP Pro Find Usage Displaying Old Results

I clicked on a component in PP Pro Client 2016 and selected "Find Usage".

It displayed many nonexistent protocols.  When I click on one of them, it reports "Can not find the item "Protocols/foo/Bar" in protocol database pp_server.com.  It might have been deleted, renamed or moved."  This error message *is* true.  I did delete or rename or move these.

My question is *why* would they show up at all then?  I restarted the PP Apache server, but that didn't do anything.  My concern is that if *old* ones are showing up here then maybe the usages that actually exist are *not* showing up.

Thank you,
Randy Stegbauer