WebGL build is completely garbled

Our app, which works fine in 5.1.0f3, just shows a screen full of artifacts in 5.2.0b2 WebGL builds.

It doesn’t even show the simple loading screen (logo on white).

http://fogbugz.unity3d.com/default.asp?711954_5i42phcvtqa1titg

Included screenshot of garbage/artifacts.

Ugh, my fault for forgetting to transfer the previous Known Issue that UI on WebGL is broken. Fixing release notes.