Kubuntu 17.04 is installed, cannot boot, wants to 'Perform MOK management', can't find the right file though. Linux-Mint boots fine.

Hi,

I can't boot Kubuntu 17.04, boot repair suggest I pass this URL: http://paste.ubuntu.com/25540028/

Boot-repair fixed a few things so that I see a screen titled "GNU GRUB VERSION 2.02~beta2-36ubuntu3.9

where I do have:

. 2 entries for Linux Mint 18.2 Cinnamon 64-bin ( one regular & one with advanced options)

. Windows UEFI bootmgfw.efi

. Windows Boot UEFI loader

-- all 4 entries above do boot into the system they indicate --

. EFI/ubuntu/fbx64.efi This one just reboot and gets me the same GRUB menu

. EFI/ubuntu/mmx64.efi This one gets to a blue screen "Shim UEFI key management" which give 10 seconds to "Perform MOK management", where I have 3 options: (i) Continue boot (but just comes back to previous screen), (ii) Enroll key from disk, (iii) Enroll hash from disk.

Those last 2 options suggest a unique 'MULTIBOOT' key to be selected. "The key will be enrolled into the MOK database. This means any binaries signed with it will be run without prompting. Remember to make sure it is a genuine key before Enroling it" (as if I could make the difference between a genuine key and a not-so-genuine one, or if I just ~forgot~ to make sure of it ...)

Anyway, I tried all directories available: all selectable KEY files apparently don't have the right format. The message is : "Unsupported Format. Only DER encoded certificate (*.cer/der/crt) is supported.

Similarly all selectable HASH files, even though they do have a *.efi extension fail. The message is: "Hash failed (did you select a valid EFI binary?): (14) Not Found.

Please advise, thanks,

--pj