GoogleApiClient.connect()' was expected to be of type interface but was found to be virtual

Question

So I am connecting to the google api client like this.

        googleApiClient = new GoogleApiClient.Builder(context)
        .addApi(LocationServices.API)
        .addApi(ActivityRecognition.API)
        .addConnectionCallbacks(this)
        .addOnConnectionFailedListener(this)
        .build();
        googleApiClient.connect();

This exact same code I am using in several places and it works well. It's not different from what you see in their tutorials. But now:

java.lang.IncompatibleClassChangeError: The method 'void com.google.android.gms.common.api.GoogleApiClient.connect()' was expected to be of type interface but instead was found to be of type virtual (declaration of 'java.lang.reflect.ArtMethod' appears in /system/framework/core-libart.jar)

The line that the stacktrace reports is:

googleApiClient.connect();

Using play services 8.1

compile 'com.google.android.gms:play-services:8.1.0'

Has anyone this this?

Answer 1

The problem comes from one of the libraries your app depends on, library that depends itself on Google Play Services as well.

That library is using an older version of the Google Play Services SDK and it still relies on the fact that GoogleApiClient class is an interface. This has changed in 8.1.0 where it became an abstract class. This breaks backward compatibility because of the transitive dependencies of libraries.

Look if that library you use has a new updated version with 8.1.0 as well, or remove that dependency if possible.

More explanation can be found here.