I have a VM setup in VirtualBox (LinuxMint 17.1). But I'm trying to boot to GParted so I can resize a partition. I'm using gparted-live-0.22.0-2-amd64.iso and it boots correctly. I've tried every option in GRUB as well as the latter menu, but I can't get past this screen:

This screen also appears during boot, before I get to the keymap selection screen:

