juned393:
Hey Guys, this is Android Mobo Geek who owns almost all brand Android Devices right from Moto, LG, Nexus, HTC to Samsung and I owned these devices before a year hence they all are running on android marshmallow hence I faced Screen Overlay Detected issues on my all android devices and this error was fu***ing my a**s from centuries but finally I came across the common solution for all devices and that is by switching android to Safe Mode and then turn on all permissions of newly installed app.
Different devices have different procedure to switch the device to the Safe Mode hence you can check from below website that how to switch to Safe Mode and turn on all permissions of newly installed app to get rid of screen overlay detected asshole
https://screenoverlaydetected.com
let's hope this may help you too until we switch to Nougat

it worked for me perfectly!, many thanks guys.
to turn ur fone to safe mode,press the power button, then you long-press the power off option which is part of the 3 displayed options which are power off,restart and air plane mode,when you long press the power off button the safe mode option pops up then click OK,i hope it helps!