16F877A to 18F4620 error

I am running my code on a 16F877, I believe I have exceeded the memory size, and migrated, or attempting to use the code on a 18F4620. I made the change for pull up resistor change, from OPTION_REG. 7 = 0 TO INCON2. 7=0. But I am not able to compile, I got this error message:

ERROR 172 C:PBP\PBPPIC 18.LIB 804: PCL, TOSL, TOSH, OR TOSU cannot be a destination MOVFF OR MOVSF.

Not sure if it is looking for some files, I am using pic basic pro, with MPSAM Window compiler

Any help is greatly appreciated.

Regards,
Imad