This is happening at a customer site, and we can't duplicate it on any of our boxes.
It seems that we have a call to _Rreadk() that works fine if the file is created with ACCPTHSIZ(*MAX4GB), but it crashes the program -- only on the customer's box -- if the ACCPTHSIZ is (or has ever been) *MAX1TB. Even if it's changed back to *MAX4GB.
(I don't know exactly what exception is being thrown, but I should know soon; the user said he'd email me the joblog.)
And everything works just fine on our V4R4, V4R5, V5R2, and V6R1 boxes.
And likewise, our QuestView terminal-based product works just fine on the customer box (it uses the same record-level access entry points used by OPM RPG, but calls them from MI).
Has anybody ever heard of _Rreadk failing like this?