The fluid xp block decreases the player's hunger value by 1 when the player is colliding with it, causing the hunger value to reach negative values and crash the game. You should add a check for this in your MGUFlowingFluidBlock class.

Ya, that > 0 check should have been there from the start, try as i might i cant get it to crash even without it though, just out of curiosity could you toss in the crash log before i close it? i just wanna see exactly whats happening, since it wont crash for me, even when the hunger is WAY below zero lol.

Oh my bad it's an incompatibility with appleskin, I apologize. If you add that >0 this issue will be resolved so I assume you don't need the log.

thats fine, like i said, it should have had the > 0 from the start, negative hunger should never happen haha, that explains why i couldnt get it to crash in dev.