From launcher when I select the newest snapshot and hit the "Play 17w50a - Latest snapshot" after a few seconds I just get a screen saying "Game Crash An unexpected issue occurred and the game has crashed. We're sorry for the inconvenience.".

Launcher Logs show that if the custom windows size is set, then it will crash, and if I disable it the game will load.

Any other version of minecraft I've selected loads fine. I've tried fresh install, and tried to have it install into a custom folder even.

Can reproduce on OS X machine as well now that I understand the issue.