Mpasmx

I've been using PBP 3.0 gold, MPASMX and MCSP for the last few months without any problems. I decided to update MPLAB to version 4.1 and I loaded XC8 C compiler. Now when I try to compile something with PBP 3.0 and MCSP I get an error "unable to execute MPASMX." in MCSP. I've manually pointed MCSP to MPASMX but to no avail. Any help would be appreciated.

welcome to the Death Spiral of legacy software
I would go back to an earlier version of mplabx , [3.55 works ok]
get pbp working again . and then try 4.1 again , don't remove 3.55 though.
usually mplabx allows multiple versions to coexist , I have not tried 4.1

ps
PBP_MPASM_Connector.exe you did try this ?
its in you pbp/ MPASM-MPLAB_SETUP folder