I solve this problem by updating my support library from
'com.android.support:appcompat-v7:23.2.0'
'com.android.support:design:23.2.0'
to the same dependencies of 23.2.1.
When I met the problem, I had not made any changes in my module built by Android Studio.
So I was so confused then I tried to update android support library.
After updating, please remember update your build.gradle
