This means the issue is most prevalent right after installation on first start when Loquiz needs to ask for Location, Camera and Photos access. So when you run Loquiz app and some other app that overlays other apps is running in the background, you might encounter a warning message. The screen overlay issue is present starting from Android 6  (Marshmellow and Nougat). From this version onward Android allows one app to write on the screen (overlay) while another app is running.

One way around it is to deactivate the app that provides the overlay.

But the best option is the following:

If Loquiz is installed and the Overlay issue emerges please just go to Settings-> Apps->Loquiz->Permissions

and tick all three:  Location, Camera, Storage.

Going back to Loquiz app (Loquiz might need to be restarted) the overlay should not be an issue anymore because Loquiz has the needed rights.

More detailed explanation for user can be  found here: http://www.howtogeek.com/271519/how-to-fix-the-screen-overlay-detected-error-on-android/