So I downloaded Honest Hearts and the update as well, but whenever I get to the loading screen and press start, I get an error saying the disc can't be read, wipe with a cloth, etc. I even took the disc, which was a bit scratched, to a store to get the scratches out, but it didn't help.

I don't know if this makes a difference, but I recently had to replace my disc drive due to the original breaking. I didn't do any modding, it was just a replacement for a broken part.