android.graphics.drawable例外”。RippleDrawable，引用自android.support.v7. widget.appcompatimagehelper.hasappingrendering

I am designing an android app. My app is working fine on above 21 API but when I started to test it on API 18 it unfortunately stopping. At the starting of Login Activity app is stopping .When I input in the Edittext app unfortunately stops. Below is my code.I am designing an android app. My app is workin