Blue screen on scene load for some Android devices

My Unity 2D project has some scenes with NGUI elements and some with only Unity sprites. Confirmed on Samsung s5 running droid 4.4.4 and a nexus 5 running droid 5, when I load the first scene that has no NGUI elements (and also no UI Root, just a regular MainCamera), all I get is a non-responsive blue screen, as in Unity background blue.

Somehow this issue does not exist on a Droid Bionic running droid 4.1.2, and the scene loads just fine.

I figure that it must have something to do with my cameras, but even adding NGUI elements to the scenes without them didn't solve the problem.

Any ideas?