Black screen on iOS device during gameplay

Hello, I’ve got a strange problem on iOS devices. In a release build of a game dugin gameplay, when swiping map or moving it around sometimes screen goes dark. All Legacy Unity GUI elements are drawn, all NGUI elements are drawn, screen reacts to swipe and pinch on logs, but everything else is black (meshes, sprites, toolkit2d elements, etc). Any idea what this might be?

It happened only on iphone 5 and ipad air 2, and after device reset problem never occured again. Before device restart even reinstalling app could reproduce the issue, but after restart it never happened again.


I would suggest logging a bug with Unity, with a small project that reproduces the issue.