Hello,

You're going to need the burn the bootloader for the PIC16F877A onto PIC16F877A chips and the bootloader for the PIC16F877 onto the PIC16F877 chips.

Their architecture, especially in terms of the flash memory, is different and is dealt with differently.

If you straighten this out you should be good to go.

I had the same problem last month and now I have less hair.



Cheers!