As specialists have discovered the reason is that Android has introduced a new feature, "Draw over other apps", in Marshmallow & Nougat. This allows some apps to drew over other apps. For example, Facebook Messenger uses this feature for their chat heads to be shown over other apps. In other words the app can show info on top of the others. Clearly, this is the cause of the annoying "drawing". Moreover it is not the only program which is functioning this way. The real issue is that when you’re running a floating app and at the same time start a newly installed one, the new one asks for permissions. Android OS does not allow changing the settings. This routine raises "Screen Overlay Detected" error.
Thus if you download a new app and install it for the first time chatting at one time in Facebook, you will get the error message at the very moment your new app asks settings permission. The screen below shows "WhatsApp" which appears to be a "floating app" and drawing over the others. "WhatsApp" is also the reason for the overlay error.
The example below shows when "Screen Overlay Detected" pops up the message contains "Open settings" option. Tapping it you find yourself in "Draw over other apps" menu. You can manually change the apps settings over by blocking "Permit drawing over other apps" function and get back. You can going through one other menu option. All these doings takes too much time especially if your Android contains dozens installed apps with "Drawing over other app" features. To know what to do you have to find out which app causes the problem to block precisely the right one.
To identify which app is the "guilty" one consider of the following:
- Which apps have you recently used? Frequently Facebook Messenger, Clean Master and CM Locker cause the error. If you use Messenger for chatting it is likely the reason.
- Which apps are always running in your device in the background? Do check CF.lumen and Twilight which use "Drawing over other app" feature when run. Is it worth to disable or suspend them to get rid of the annoying message?
The list in the picture shows all apps which are permitted to draw over other apps. If you have figured the right one out, you can simply disable it when getting the error and go ahead.
Certainly, to block one application is not necessarily guaranteed the end your worries. Sometimes the cause of this error are several but just one apps. Hence to find out the "culprits" is not an easy task to do. In these cases the easiest way to fix the issue and run a new app is to disable everything re-enable those apps that you actually need. Such a method will definitely work.