Can't activate nor deactivate any administrator permissions outside of safe mode I just upgraded my Nexus 5 from 4.4.4 all the way to 6.0.1 and ran into a problem: I can't change any administrator settings outside of safe mode. I wanted to activate it for a screen lock app but the 'activate' button and 'cancel' button don't respond to touch, the same with any app in the list, whether to activate or deactivate. Screen orientation does not matter. In safe mode I can only see the apps already activated, none of which I now dare deactivate fearing I won't be able to reactivate them.

Can anybody help me with this?
If you are using an app such as Facebook Messenger, CF.lumen, Lux or Twilight that draws over the screen, you'll need to stop them doing so in order to interact with secure settings pages such as the device administrator activation/deactivation pages.

For example, in Facebook Messenger, you would either close all chat heads or go to the Facebook Messenger settings and deselect 'Chat Heads', or in CF.lumen you would disable the overlay by pressing 'Disable' in the persistent notification.