I work in the IT department of my university and we work on an app that installs the correct setup for the eduroam WiFi (maybe you have heard of it).
However I have a problem running it on my own LG G4 with Android 6.0. When installing the compiled *.apk it doesn't ask for any permissions although they are set in the AndroidManifest.xml. It was working on all previous Android versions.
Is it mandatory now to ask for permissions at run time?
If your target SDK version is 23 then you need to ask for "dangerous" permissions at run time.
If this is the case then you should be able to see that no permissions have been granted if you go to Settings > Apps > "Your app" > Permissions.
If you don't want to do implement the new system yet then you can reduce your target sdk version to 22 to get the old permission system. You can still compile with sdk version 23 though.
See the documentation for more information.