Comment 7 for bug 1511974

I found a solution!
It seems to have been as simple as delete purge xserver-xorg and then reinstall xserver-xorg

This fixed the issue for me.
However, in the meantime I also manually updated my linux headers to the latest version (for wiley) because they would not update correctly by just doing sudo apt-get install linux-headers-generic.
So I don't know if that contributed or not...