Ubuntu all of a sudden fails to boot on ThinkPad T430

Not booting

Running Ubuntu on my T430 has been fairly straightforward and great until just now. After I used my Windows for some days, Ubuntu all of a sudden fails to boot. After I select Ubuntu in GRUB, I get the following screen:

Error: File "/vmlinuz-3.13.0.24-generic.efi.signed" not found  
unalinged pointer to 0xd0a26c68  
Aborted. Press any key to exit.

Neiter does a live system

To fix that, I tried to launch a live Ubuntu to do things like update the packages and reinstall grub. But the live Ubuntu failed to boot as well, it only gave me the GRUB command line. Unfortunately, I don't know what to do with it.

What now?

I have no idea where a problem like this could come from. In Windows, Lenovo showed a UEFI-Update wich I thought I had deselected, but it might just have slipped in. Anyway, can a problem like this be triggered by a updated UEFI?

Starting in recovery mode doesn't help. I cleaned old kernels to have space on my /boot - partition again so I cannot try older kernels. Until now, the current kernel just worked for me.

As I don't have a OS I can work with in the moment I would be very grateful for any tips, hints or suggestions.

Solution 1:

The problem with the USB was obviously a broken ISO. My bad, I should have checked better. So the live system is working now.

With the live system, I got new information and the issue seems to be more about my /boot-partition than my UEFI. As I didn't want to essentially edit the whole question, I opened a new one.

I want to thank @MartyFried a lot for his help.