Google maps v2: Authorization failure

For me help this, if simple: When you work from Android Studio you write your Google API key in file google_maps_api.xml but Android Studio show you only key file for (debug) version in Project Manager. You need place your key in

\app\src\release\res\values\google_maps_api.xml

file too (like you place in place your key in

\app\src\debug\res\values\google_maps_api.xml

)

Activate the Google Maps Android API v2 service in the Google API's console. Also, after making changes do a full reinstall of the app on the device/emulator.

When you set up your API key, the package name is the value of the package attribute on your manifest, not the application name.

This (com.foo):

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.foo"

Not this (com.foo.MyApplication):

<application
    android:name="com.foo.MyApplication"