I think it's very likely this is (at least in some cases) related to
nvidia drivers.
I first got this problem while trying to fix a problem with ubuntu
freezing after initial login described
[here](http://askubuntu.com/a/760935/207604). I did "update" > "upgrade"
> "upgrade nvidia drivers" as per
Any update on this? Seems mad that there's a "Critical" error on ubuntu
that's been around for over two years and no one from Canonical appears
to be trying to fix it. A sad reflection on the current state of ubuntu.
I'm on 16.04 and with LVM and LUKS and having the same problem. I can boot
succe