Android M permission dialog not showing

It took my whole day to find out what caused the problem. The original answer helped me.

I fixed by adding tools:remove="android:maxSdkVersion" like this:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" tools:remove="android:maxSdkVersion"/>

I experienced the same issue because I was using the negative value as a REQUEST_CODE.

requestPermissions(new String[]{android.Manifest.permission.CAMERA}, -1)

After using positive value, the system showed the dialog. Hope it helps someone.

I experienced the same issue but later I realized I forgot to add the permission to the manifest file. After adding the uses-permission tag, the system showed the dialog. Maybe helps someone.