[SOLVED] Android PlusOneButton does not initialize

Android PlusOneButton does not initialize

I am trying to include a PlusOneButton to my Android App. I created the app on google cloud console with the SHA-1 from my debug.keystore as described by google (https://developers.google.com/+/mobile/android/getting-started?hl=en).

In my XML-Layout I add the +1-Button:

<com.google.android.gms.plus.PlusOneButton
    android:id="@+id/btnPlusOne"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    plus:size="standard" />

In my Activity I override onResume() method. Of course I retrieve the object via findViewById(...) first:

public void onResume() {
    super.onResume();
    btnPlusOne.initialize("http://www.google.de", REQUEST_CODE_PLUS_ONE);
}

I also give the permissions in Manifest:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.USE_CREDENTIALS" />

But if I start my app, the PlusOneButton looks gray. If I click on it, a progress bar appears in the button and runs infinitely. On Logcat I get this message:

18367-18367/? W/PlusOneButtonView﹕ Failed to establish connection with status: 8

If I check this in API-Doc (http://developer.android.com/reference/com/google/android/gms/common/ConnectionResult.html#INTERNAL_ERROR) it says something like internal error. But currently I have no idea what could solve this problem?

Solution