In my case the problem was an entry in fstab that was no longer valid. Commenting it and rebooting (systemctl default didn't work) did the trick.
Michael: the bug has been marked as "not ours" upstream. This seems fine, but it would be really cool if the joyrnald had a more explicit message about this issue. I think a wishlist bug upstream to improve this would be really cool. -- Lisandro Damián Nicanor Pérez Meyer http://perezmeyer.com.ar/ http://perezmeyer.blogspot.com/
