After adding compile \'com.android.support:support-v13:21.0.+\' to build.gradle, I had some conflicts on building my app, so I had to add m
compile \'com.android.support:support-v13:21.0.+\'
build.gradle
What i did was too update the compiling library in app level gradle file.
compile 'com.android.support:multidex:1.0.0'
I updated it too
compile 'com.android.support:multidex:1.0.1'
and it worked fine for me. Maybe this helps someone.