You probably want to ask in forums of your mods and not official game forums. The game doesn't officially support the mods.

Originally posted by Guimillen:

I installed, EpicLoot, BetterCreative mods, Command Manager, but now i cant jump.

If I had to guess, its command manager.

I would take out all the mods and test them one at a time, its best to test issues 1 at a time to reduce factors.
Uninstall game, delete folder , re-install to default, trial each mod one at a time.
Unfortunately each update of the base game may break mods, the devs are working on the base, and at this time no support is given to mods, at this time... the game is still being developed.

It could be because you or your character is white.

Originally posted by McCloud:

I find it best to not jump when playing any game.

Honestly when one jumps while playing games they are exercising and thus staying in shape despite the fact that they are playing a game. I never thought of doing this myself and honestly if more of us video gamers would partake in this particular activity we may not get such a bad rap. Meaning our moms or wives (yeah right who we kidding) can no longer say that we are just lounging and gaming when in fact we are actually exercising more than our fingers. This may very well spark a movement to allow more people to play games and thus more games means more money to create said games thereby resulting in a true win win.

You probably want to ask in forums of your mods and not official game forums. The game doesn't officially support the mods.

I find it best to not jump when playing any game.

Disable them one at a time to see which one is doing it. I doubt that's it's Epic Loot because that one seems popular and I haven't heard of any jumping complaints. Also check to see if somehow your jump key got remapped.