Unable to turn Private Mode on. I am not using ART runtime and have previously set up private mode. I am not even able to "switch" it on, it is almost as if it is permanently turned off. I know how to access it, and have turned it on previously. I have read other forums discussing that if i am using runtime ART that it needs to be disabled and turned to Dalvik in the Developer Options. Does anyone else have this problem or know the solution to it?