I have Ubuntu installed as the sole operating system on a Lenovo Y70 touch laptop. It was version 16.04. After a recent update, the system would not start. Instead, I am presented with a blue screen saying
verification failed: (0x1A) Security Violation. I can't fire up a terminal, boot from a live USB or use an alternate screen.
I went into the BIOS and attempted to disable UEFI. But the change won't stick. It always reverts to a UEFI boot.
I don't have a recovery disk, and Lenovo won't provide a way to revert to Windows. Has anyone come across this problem before?