Almost everyone is uninstalling some apps from their device to get rid off Screen Overlay Detected popups. But to be true Screen Overlay is basic feature used by almost every application.

Messenger Chat Head, Inbox Messages Preview and Whatsapp Messages Popups are all examples of screen overlay feature, so you can't uninstall all application to resolve Screen Overlay Detected popups on your device...

You just need to manually turn off screen overlay of all applications in your device, Almost everyone is uninstalling some apps from their device to get rid off Screen Overlay Detected popups. But to be true Screen Overlay is basic feature used by almost every application.

Messenger Chat Head, Inbox Messages Preview and Whatsapp Messages Popups are all examples of screen overlay feature, so you can't uninstall all application to resolve Screen Overlay Detected popups on your device...

You just need to manually turn off screen overlay of all applications in your device, Follow following settings to turn off screen overlay of android application:

> Settings

>Application Manager

>Click on Three Dots (Top right corner) & Select Draw Over Other Apps

>Turn off screen overlay of all apps one by one

This must solve the issue of screen overlay in your device...

Try This:

1. Open the Settings
2. Tap the magnifying glass at the top right
3. Enter the search term “draw”
4. Tap Draw over other apps
5. Alternative route: Apps> [gear  icon]> Draw over other apps

Let me us know if that works. 

(source)