Bad guess Dwayne... Microcode studio will support every PICs on the market. If he's not in the list, you can it if you edit the pic.ini file in the MCS directory. Maybe you use an older version.

If you want to compile with PIC18F serie, you must set MPASM as assembler in the View > PicBasicOption >assembler tab. In case MPASM is not set, PM will be used for. As is seems PM is not support 18F serie for now. This is why Dwayne.

Don't be affraid of MicroCode Studio. This is the best i know on the market... better than the shi... MPLAB. But again, it's my own opinion here.