[Shu-yan Kok]

After upgrading to Android 6.0.1, the apps on my phone could no longer access to my storage, camera, microphone etc. I followed the steps when it prompted me to grant permission for apps to access to storage, it said I have to turn off screen overlay in Settings but it didn't work.

[NerdgrlApps]

Try to do the following:

1. Enable Developer options: Settings -> More -> About device -> Build number -> Tap on it 7 times

2. Settings -> Developer options -> Drawing -> Simulate secondary displays -> then select None

[Shu-yan Kok]

Thanks. but I've tried all of the steps

[Mooncatt]

Are you running anything like a screen filter? I.e. Those virtual window tint apps that artificially reduce screen brightness by putting a tinted virtual overlay drawn over the entire screen.

If so, you need to exit the overlay app before you can allow other apps access to the SD card. It's a security measure built into Android. Lux is a popular app that causes this popup, but any app with similar functions could do so too.