This just happened to me during a "routine" upgrade of a 20.04 system.
Setting up grub-efi-amd64-signed (1.142.9+2.04-1ubuntu26.7) ... Installing grub to /boot/efi. Installing for x86_64-efi platform. A window pops up: GRUB failed to install to the following devices: /dev/nvme0n1p1 Do you want to continue anyway? If you do, your computer may not start up properly. Writing GRUB to boot device failed - continue? (saying "no" just loops back to the same screen) grub-install: warning: Internal error. grub-install: error: failed to register the EFI boot entry: Operation not permitted. This is the last info line before the error when manually running grub- install: grub-install: info: Registering with EFI: distributor = `ubuntu', path = `\EFI\ubuntu\shimx64.efi', ESP at hostdisk//dev/nvme0n1,gpt1. No idea what to expect when I reboot. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1872212 Title: grub-install: Operation not permitted To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/grub2-signed/+bug/1872212/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs