If a BMP resource is missing, it could be for one of three reasons:
1. As Barbara said, the BMP could be corrupted, and the file cannot be read.
2. The BMP can't be accesed. Move the main file to RAM.
3. The BMP id could be changed. The ID is a number that identifies the bitmap. The resets do unnimaginable things to stored data, and the open data is the first to be damaged. I'm not the expert, DON'T BELIEVE ME, but i think a reinstalation of the PRC file will not fix the problem. I'll repeat: DON'T BELIEVE ME, IT'S ONLY AN IDEA.