I remove 10_linux_proxy this file. But below command can not help to create this file. sudo apt-get install --reinstall grub-common sudo update-grub.
Then I can only use boot-repair software to reinstall GRUB. Now it is OK. No error message anymore. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/998835 Title: error: unknown command "gfxmode" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/998835/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs