Was receiving this error this last week after changing the primary permission list on some accounts in PIA.
[Open Query] [CQryStmt::Prepare] QDM could not load query definition [ PUBLIC.PT_SEC_PLIST_USERS ]
I was trying to run a query to see which users belonged to a permission list.
Turns out that the reason was because the primary permission list that I assigned to some accounts did not have access via definition security to the PeopleTools Group ID. (also, make sure you change display view to Yes.
After adding the primary permission list with access to the PeopleTools group + display view set to Yes, then the queries in PIA worked fine. Also, make sure the primary permission list is under the query process groups in PIA as well.