I'm afraid this looks like a bad motherboard/firmware; it appears to have simply "forgot" that it should boot grub. Unless you can identify some particular software action that seems to cause it?
** Package changed: grub (Ubuntu) => grub2 (Ubuntu) ** 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/1561842 Title: Grub bootloader disappears after a seemingly random amount of restarts/shutdowns. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1561842/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs