ok, so the term.log.3.gz shows the upgrade from May 18, and it appears that at that time you *did* have grub-efi-amd64-signed installed and probably also shim-signed.
The timestamp on the grubx64.efi is from July 2, which is when you say the problem started. But your apt log for this time period does not show any package changes at that time. Please also attach /var/log/apt/term.log.2.gz for completeness. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1489987 Title: Secure Boot failed on Ubuntu 14.04 on Dell E7440 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shim/+bug/1489987/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs