Comment 3 for bug 515950

This is not an error of the bootloader, but of a broken initramfs generated while udev was in an unconfigured state. This is not supposed to be possible, but I've seen this error before as well; reassigning to apt, and marking as a duplicate of bug #453678.

To work around this error, please select the previous kernel from the boot menu, open a terminal, and run 'update-initramfs -u' to regenerate the initramfs for the 9.10 kernel.