Error in Fragment: "Already managing a GoogleApiClient with id 0"

You should call stopAutoManage() in the onPause() method of your Fragment like so:

@Override
public void onPause() {
    super.onPause();

    mGoogleApiClient.stopAutoManage(getActivity());
    mGoogleApiClient.disconnect();
}

You should call stopAutoManage() in the onPause() method of your Fragment:

@Override
public void onPause() {
    super.onPause();
    mGoogleClient.stopAutoManage(getActivity());
    mGoogleClient.disconnect();
}

To avoid further issue

@Override
public void onStop() {
    super.onStop();
    if (mGoogleApiClient != null && mGoogleApiClient.isConnected()) {
        mGoogleApiClient.stopAutoManage((Activity) context);
        mGoogleApiClient.disconnect();
    }
}

I faced a similar issue when I placed a login button in two different Fragments belonging to the same Activity.

I solved this issue by assigning different ids to each automatically-managed GoogleApiClient.

For example, in Fragment 1, while creating my GoogleApiClient object I assigned 0 as the id:

mGoogleApiClient = new GoogleApiClient.Builder(getActivity())
                    .enableAutoManage(getActivity(), 0, this /* OnConnectionFailedListener */)
                    .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                    .build();

In Fragment 2, while creating my GoogleApiClient object I assigned 1 as the id:

mGoogleApiClient = new GoogleApiClient.Builder(getActivity())
                    .enableAutoManage(getActivity(), 1, this /* OnConnectionFailedListener */)
                    .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                    .build();