Dave,
If you don't mind me asking, are you using the UMCBuild application to create your bootloader .hex files or are you building them manually in MPLAB?

I've just read thru the documentation and have attempted to create a .hex file using the UMCBuild application but needless to say I'm struggling. The application says it can't find the MPASM executable, something the docs says it should be able to do if I have a working environment (which I do). I suspect the issue is that it's looking for MPASM.exe while it's now called MPASMX.exe.

I tried adding the path to MPASMX in the [PATH] section of the UMCBuild.ini but I get either Can't find MPASM executable or Can't find MPASM path. I tried making a copy of MPASMX.exe, renaming it to MPASM.exe but still can't make it work.

Would you mind sharing some of your knowledge regarding the UMC?

/Henrik.