When I am entering one of my worlds, it just immediately crashes the game. (Crash Report attached)
In that specific world i have absolutely nothing (It's a superflat) and only a datapack with some functions and a loop function tag.
Also included a zip of my world folder just in case you need to look up for the problem.

On 17w50a this issue didn't happen.
But I hope it gets fixed, currently i can't log into my world