Everything was working fine and was using 2.09. I switched to 2.10 and just started to play again tonight and when I tried to load my world, the game said that it was corrupted because of a mod. Please look into this as I'm trying to recover my world.

Ok.. can you be a bit more specific as to how it hapend, perhaps some screenshots of the game saying that it is corrupted and a log file wouldn't hurt, im not trying to be a dick but saying that it broke without showing me a log or something makes it really hard to fix my bugs.

I just checked my log files and can't find any reference to that. However, I was able to get an earlier version of my world back when I removed the mod and it's config files. I can replicate the problem again, but it's working now. If you want me to try, let me know.

OK, I noticed something. Is there a way to convert MJ into RF?

MJ is no longer supported and is removed from build craft update your mods. Also what forge version are you using?

I'm playing FTB Infinity which is for 1.7.10 and the mods are all updated for it. It's not 1.8.x yet as those mods are not updated to that version. I use Forge 10.13.4.1448.as it came with the pack.

hmm, ill run some tests when i get home and see what i come up with, this should not happen btw, it will only happen if some mod is messing with the Remapping event that i use to convert the mod id for PC.

I could test it again to see if it comes up, but will have to be during the weekend. All I can tell yo is that I went from 2.08 to 2.09 without deleting the old configs and when I upgraded to 2.10, that's when it happened.