Ubuntu 14.04, just updated from kernel 3.13.0-40-generic to 3.13.0-43-generic and now I can not boot my laptop.
It seemed that the new kernel came with some Navidia drivers that caused this problem. Somehow the update destroyed my previous installation (3.13.0-40-generic) as well and I could not boot it from grub either. Had to move further back to 3.13.0-39 to boot.
Please advice what I should do.