So I use one pic (18F6520) on one board and I use Microcode Studio Plus 3.0.0.5, PB Pro Compiler 2.50 and a MELabs usb programmer.

I set all this up about 2 yrs ago and haven't changed the set up at all. I regularly change the firmware, load it, run it and don't give it much thought.

Until today...

I grabbed a board to load a program onto and everything indicates that it loaded fine but it doesn't work. I was loading a known program so that wasn't the issue. I regularly load this program to work with. I tried several other programs same problem.

I finally went back to several known hex files that weren't compiled by Microcode Studio recently (but were compiled by it in the past) and they loaded fine. There are no known changes, to me, so I'm completely stymied.

I also tried to just compile the program and then open it from my programmer.

If you haven't guessed by now, I'm not a professionally trained programmer so I know just enough to be dangerous.

Any help is hugely appreciated.

Thank you,