I will add that it seems like 10.2.500.8 has fixed the BPM error that we were receiving too. Our live environment is still on 10.2.500.7 and the error still periodically shows up.
It appears to have fixed our problem (the main one this ticket was for) in the main Epicor, at 10.2.400.19. We still have an issue with the MES screen though, launching the same Web Form.