I had this issue where I overflow the 64k method limit in Dalvik when compiling all the library I used. I started to have this issue when I imported the Support
You can open the terminal and run command gradlew app:dependencies to test which dependencies are already included in the others as transitive dependencies for your project along with the respective versions of each.
For example I got the following dependency chart for one of my projects for the com.android.support:design library I used:
+--- com.android.support:design:23.3.0
| +--- com.android.support:appcompat-v7:23.3.0
| | +--- com.android.support:support-vector-drawable:23.3.0
| | | \--- com.android.support:support-v4:23.3.0
| | | \--- com.android.support:support-annotations:23.3.0
| | +--- com.android.support:animated-vector-drawable:23.3.0
| | | \--- com.android.support:support-vector-drawable:23.3.0 (*)
| | \--- com.android.support:support-v4:23.3.0 (*)
| +--- com.android.support:support-v4:23.3.0 (*)
| \--- com.android.support:recyclerview-v7:23.3.0
| +--- com.android.support:support-v4:23.3.0 (*)
| \--- com.android.support:support-annotations:23.3.0