错误 - 必须实现OnFragmentInteractionListener - 但我想我有？

I am using multiple fragments in an activity, and after adding another just the same way as I added the first I am getting the auto-generated 'must implement OnFragmentInteractionListener' exception. The app worked initially without this error but after running it a second time the exception is thrown. As far as I am aware I have implemented them correctly. Any help would be greatly appreciated.I am using multiple fragments in an activity, a