Use AppCompat instead of ActionBar
diff --git a/app/src/main/java/org/apache/taverna/mobile/activities/LoginActivity.java b/app/src/main/java/org/apache/taverna/mobile/activities/LoginActivity.java
index 6bcfd2a..291d3fd 100644
--- a/app/src/main/java/org/apache/taverna/mobile/activities/LoginActivity.java
+++ b/app/src/main/java/org/apache/taverna/mobile/activities/LoginActivity.java
@@ -34,7 +34,7 @@
 import android.os.Bundle;
 import android.preference.PreferenceManager;
 import android.support.v4.app.Fragment;
-import android.support.v7.app.ActionBarActivity;
+import android.support.v7.app.AppCompatActivity;
 import android.util.Base64;
 import android.util.Log;
 import android.view.LayoutInflater;
@@ -56,7 +56,7 @@
 import java.nio.charset.Charset;
 
 
-public class LoginActivity extends ActionBarActivity {
+public class LoginActivity extends AppCompatActivity {
     private static final String TAG = "LoginActivity";
 
     @Override