Recently Android Support Library has been updated to v21.1.1. There were some changes and you can see the changed via the link: https://developer.android.com/tools/support-library/index.html#revisions One thing I have notice is new AppCompt* classes for appcompat library. Now you need to use AppCompatActivity instead of ActionBarActivity. It supports support library action bar features. ActionBarActivity now has been deprecated. I think this kind of too often changes in framework makes us developers annoying. Some people might just start to use ActionBarActivity.