Do you mean it freezes after choosing to boot Ubuntu from the menu? Can you get a picture of the exact error?
** Changed in: grub2 (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1280462 Title: booting randomly fails on a dual-boot HP ZBook To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1280462/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs