Maybe this will clear it up... I have products for both the 12F629 and the 18F2520. (both are written in PBP) I need to be able to program both of these when necesary. Someone else is replaceing me while I go back to school and they demanded use of C18, so it got here and I installed it. I got the programs to compile and tested them using MPLAB SIM. I'm now going back to my projects and trying to program chips using PBP for both projects and I'm unsuccessful. I'm now trying an extremely simple program in the 18F2520 and I can get it to compile but when I try to run debug, it gives me the afore mentioned error. When I just program it acts happy and says everything went well but then the program doesnt run.