On Fri, 23 Apr 2021 17:15:16 +0100
Nick Rickard <nick@???> wrote:

> Do you still have the old kernel(s) installed on the machine?

Yes, but AFAK these only accessible via grub stage 2 under options
>
> If so, this guide should enable you to select the older one:
https://www.calazan.com/how-to-set-an-older-kernel-version-as-the-default-in-grub-during-bootup-ubuntu-12-04/

Same problem as I don't have access to /.
Vague memories of having done that/similar in the distand past.
then it was just update-grub/grub-update and all worked
>
> Although maybe I've misunderstood quite how the kernel problem is
> causing the grub problem? I do remember having an upper/lower case
> problem with grub some time ago. The solution was along the lines of:
>

> set cmdpath=(hd0,gpt1)/efi/devuan       [previously EFI uppercase]
> set prefix=(hd0,gpt1)/efi/devuan
> normal

>
> at the grub prompt.
>
> I suspect that's unlikely to be a complete solution, but maybe a few
> hints in there?

Yes, basically what I've tried, but there s no /efi/devuan.
I've just had no success being able to access any of the file system.

i'm begiing to think that if this sort of problems keep recurring, it
will be a step back to the future from the time when the first hing you
did after installing a system was to created a boot floppy; boot cd/dvd
these days.

Any way, Thank you.
I've decided to risk it and attempt an OS re-install despite the
rebuilt mailer requiring three attempts to get a booting sstem.