In the last days we had the situation that a website reported 404 mobile URLS that were neither ever existing nor used anywhere. These URLs seemed to be wrongly generated ghost URLs by Google.
If you should run into that problem you should have a look at: https://productforums.google.com/forum/#!topic/webmaster-de/5BXorTQb4lQ
As it seems this has been a mistake and will be solved soon.
