Snow after playing "Arena4 - Gelatinous Cub Deity"? This is fixed.

Wow that was a weird one!

After playing (and dying) in that funky Arena you can no longer play the game: you'd get snow then crash until you reset progress.

Here is what was happening:
Arena 4 had its exit spawn in the wrong place, as a result McD was being respawned in the closest location which was near level 1, but on certain machines the respawn was throwing poor lil macky to infinity and beyond resulting in physics freaking out (NAN collider) and the camera following it in the netherworld of float error causing weird stuff in the view frustrum which Unity turns to snow.
So the UI was fine, the 3D camera was snow.

Solution: move the respawn point close to the navmesh so it's within the 2 unit radius.
R.I.P. weird glitch.

Thanks to Will and JY help so they get goodies.