Comment 35 for bug 1430625

I am on Kubuntu, with a hybrid Intel-NVIDIA card.

I have upgraded recently from 14.04->14.10->15.04, all in immediate succession. Upgrade process went without a problem and I was able to use the computer for a few days. Then once this "ACPI PCC probe failed" message appeared, but the boot process went well. After another day or two, now this message appears and says "Welcome to emergency mode! After logging in type "journalctl -xb" to view system logs, ... ... .. .. ... bal bla blah, asking for root password.

But I could not boot at all. A "systemctl default" choice also does not allow me to boot. Now the machine is unbootable.

How can I fix it?