After upgrading to Ubuntu 14.04, I get this error:
error: symbol 'grub_term_highlight_color' not found grub rescue>
Other instructions on how to deal with this seem to be no use to me because I can't even boot a live USB disk - I get the same error (I have USB first in my BIOS boot order and have successfully booted this way in the past). The error even comes up if I try to enter the BIOS menu at boot.
As far as I can tell I'm stuck in the GRUB rescue prompt. So I started looking at how to boot from it and tried following these instructions
grub rescue> set prefix=(hd1,3)/boot/grub grub rescue> insmod linux grub rescue> linux /vmlinuz root=/dev/sdb3 ro grub rescue> initrd /initrd.img error: no such partition.