What you call it is not as important as simply calling it something other than what Adagio calls it. I'd suggest keeping the part before the "." and renaming the 3 Character extension as in "APPOSTP.XXX" would become "APPOSTP.OLD-renamed to solveYrEnd issue".

Wouldn't hurt to backup before you rename and Data Integrity Check after you rename.

Good luck, Pete

PS: If all goes well you should go back and remove the renamed file or if you're really being safe, temporarily move it to a holding folder to be deleted later.