Public bug reported: The Live CD or Live USB for Desktop Amd64 when booted flash the error "prefix is not set" an then Display the menu ("try without installing/install/check disk"). Selecting any option just results in a black screen. The purple splash doesn't appear for the grub menu or after selection.
This bug seems to affect some Sandy bridge laptops. the 32 bit version works fine on them. Workaround: installing grub onto the live USB manually fixes it. See http://ubuntuforums.org/showthread.php?t=1841496 Laptops affected IdeaPad Z570, Acer 4755(workround confirmed on this) ** Affects: ubuntu Importance: Undecided Status: New ** Tags: boot grub live usb -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/851958 Title: Natty (and meerkat) amd64 desktop live CD/USB fail to boot grub correctly: error:prefix is not set To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/851958/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs