Boot impossible after partial update

[susejunky]

@Giorgio_os

Is secureboot enabled in your UEFI and if so will disabling it change anything?

[Giorgio_os]

@susejunky

Do I understand this correctly: If you switch on your machine you will end up with that screen?

Yes.

To start from the SuperGRUB disk are you invoking the BIOS Boot Selection (by pressing some special key on startup) and select the SuperGRUB disk for startup there?

No special keys.

In first screen I select Detect and show method

After a while a lot of lines appears and I select *openSUSE Tumbleweed (on /dev/sda8)

Does the BIOS Boot Selection offer any of the operating systems installed on your machine (e.g. MS Windows, Mint, openSUSE Tumbleweed, …) and if so can you select them and will they start?

In the past there was a list of probably 4 to 6 items. Now is completely empty.

[susejunky]

@Giorgio_os

In first screen I select Detect

Which first screen (my guess: this is already the SuperGrub disk booted) ?

How do get the SuperGrub disk started?

[Giorgio_os]

@susejunky

Which first screen (my guess: this is already the SuperGrub disk booted)

Yes. Exactly the first screen after SuperGrub complete the boot.

How do get the SuperGrub disk started?

I set boot from usb that contain SuperGrub.

[Giorgio_os]

Anyway the problem is solved in a simple and “strange” way: simply installing again Tumbleweed.
I’m not sure because a lot of try I did but the main difference is that in last installation I set EFI boot (in previous one probably I left default boot). Anyway as soon as installation completed I get back boot screen with all os installed.