It might be my Computer, it might be due to the fact that im using the BETA versions of Mac os X. But 1.12 worked without problems and 17w34b crashes when Im trying to load a world.

Heres what I did:
Before I started the latest snapshot I created a new directory for Minecraft to start in. After the game started I created a new world with the word type Custom and edited some of the world generator settings in page 3 and 4. In the generation process the game got stuck at around 90% and then it crashed. I also tried generating a world with normal generation settings but that didn't worked either.

And I know that you guys said that Mac os X has a higher chance of hard crashing but that kind of crash actually stops me from playing with the new snapshot completely.
Here a link to an one minute long Youtube video from me with that problem: https://www.youtube.com/watch?v=P3vTUpvPBR0