Bootloader problem.

[Bruce]

RB3 is the LVP pin. Make sure you're not setting LVP ON at the time you program the boot-loader .hex file into your F877 with your PicStart Plus.

[Peter Oors]

RB3 is the LVP pin. Make sure you're not setting LVP ON at the time you program the boot-loader .hex file into your F877 with your PicStart Plus.

This was indeed the problem. Now it works fine.
Thank you Bruce.

Mister_e, leaving the config fuse didn't harm.....

Thanks to all of you.