I run the following two commands. It purged and reinstalled grub and it solved my problem.
sudo apt-get purge grub grub-pc grub-common sudo apt-get install grub-common grub-pc -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1069856 Title: error: cannot find a GRUB drive for . Check your device.map. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1069856/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs