Databinding error: Only one layout element and one data element are allowed.

I solved my issue. This error appears when there is more than single element in the layout tag:

Wrong:

<layout>
     <data>
          ...
     </data>
     <LinearLayout>
          ...
     </LinearLayout>
     <LinearLayout>
          ...
     </LinearLayout>
</layout>

Correct:

<layout>
     <data>
          ...
     </data>
     <LinearLayout>
         <LinearLayout>
              ...
         </LinearLayout>
         <LinearLayout>
              ...
         </LinearLayout>
     </LinearLayout>
</layout>