Well I got same issue and still not able to fix it. I guess it’s some kinda Intel Atom CPU problem with Unity engine but really have no any solution on it.
I wish there could be someone that can help us to fix this. ><
We fixed a x86-specific bug in the scripting runtime that causes freezes. The fix is in recent 4.6 and 5.3 releases, look for patch release note “Fixed NullReferenceException on x86 devices running Android 5.0 or newer”.