Sounds like there is an error in query expression for the RptParameter dataset.
You are On Premises, so check the reports DB on the SQL server, to make sure that exists. If you don’t have access to the SQL server, follow the directions in the following post, on how to make a sub-report that connects directly to the DB. But when you get to the part about selecting the DB (#8 in the figures), choose the DB that holds the temp report tables. It’s whatever it was named when the App was deployed in EAC.
Then in the query Designer (after step 16 above), Scroll to see if the temp table is there.
