Problems with Data Binding

After I hooked up button to SoundViewModel.onButtonClicked() with the lambda expression as it was shown in the book, my app stopped to work.
I have got a lot of mistakes related to data binding. Here is the screenshots.
When I comment the lambda expression in list_item_sound.xml everything gets back to normal.

When I first used databinding in the BeatBoxFragment it automatically imported it after I reboothed Android Studio (because it did not do anything I had to reload it) :
import ws.tilda.anastasia.beatbox.databinding.FragmentBeatBoxBinding;
import ws.tilda.anastasia.beatbox.databinding.ListItemSoundBinding;
but the package itself is not created in the root of the project.

What is the problem here and what should I do to fix it? Seems that onButtonCLicked() is not detected…

Oh I figured it out!
I made a mistake in the name of the method onButtonCLicked() (with the capital L)in the test and auto created it in the view model file. And then in the layout file wrote onButtonClicked() with the small L.