During two Ubuntu 14.04 upgrades, both on a Mac (so needing an EFI boot), grub was borked after the install resulting in a grub rescue prompt when booting.

The actual error was error: symbol 'grub_term_highlight_color' not found.

Needless to say I couldn’t get the system to boot from this prompt.

I had a Fedora boot USB stick laying around, but using that did not really fix the problem, in any case I could use it to copy off /home if I could not rescue the system.

HOWEVER, the following procedure worked great!

  • Download super grub disk;
    • 1.4 MB download!
  • Copy it to an USB stick: dd if=super_grub_disk_hybrid-1.98s1.iso of=/dev/sdb;
  • Boot from this USB stick;
  • In the boot menu, choose detect OSs;
  • Boot you newly minted, unbootable, Ubuntu 14.04;
  • If all goes well it should boot Ubuntu and you can log in;
  • Install and use boot repair;
  • If you use EFI, check this: https://help.ubuntu.com/community/UEFI.