From f3 menu:
8x Intel(R) Core(TM) i7-4700MQ CPU @2.40 GHz
Java 1.8.0-25 64bit
Just playing in a world created before 18w14b, when it unexpectedly crashes. Seems to have to do with a zombie - I can get back in the world but I'm not fast enough to paste the /kill command to get rid of it, and time until crash gets shorter each time i join the world.
EDIT: The difficulty is on Peaceful - there are no zombies.
MC-124123 Crash upon loading world: Non [a-z0-9/._-] character in path of location: minecraft:Zombie