Trying to fix my bootdisk on my Ubuntu 22.04 laptop

[sitethief]

This morning I could not get into my Ubuntu when starting my laptop, it complained about a missing boot drive (iirc)
I used a USB drive with Ubuntu live to get access to the system and be able to run Boot Repair

Boot Repair info: https://pastebin.ubuntu.com/p/Q9jcfxcR9G/

I was able to mount my LUKS volume by running

sudo cryptsetup luksOpen /dev/nvme0n1p3 myvolume

which mounted it to

/media/mint/41843ba2-{long hash here}

I copied out my home folder using rsync to my separate desktop, so that data is back-upped for now. If I can't fix the boot disk I can always install 24.04 and go from there.
But I rather restore my system somehow.

What is my next step to possible restore my system?

[sitethief]

Btw, a while back I switched to Liquorix Kernel (6.8.7-2-liquorix-amd64 I think) to solve some graphics driver issues I had.
No idea if that plays any role here though, had no complains about it so far.

[currentshaft]

What is my next step to possible restore my system?

Probably posting what the problem actually is. A vague "complaint about a missing boot drive" is a mystery and we're not detectives. How about the actual error message, for a start?

[sitethief]

Probably posting what the problem actually is. A vague "complaint about a missing boot drive" is a mystery and we're not detectives. How about the actual error message, for a start?

All I had was "Default Boot Device Missing or Boot Failed"
Looked exactly like this picture
https://i.redd.it/by6g23i3n0cc1.jpeg

[currentshaft]

At what boot stage? Do you see the GRUB menu? Can you select a previous kernel version from it?

The boot repair output shows data partitions are intact, so it may be as simple as booting to the last known working configuration.

[sitethief]

At what boot stage? Do you see the GRUB menu? Can you select a previous kernel version from it?

The boot repair output shows data partitions are intact, so it may be as simple as booting to the last known working configuration.

I have no boot options for the current installation at all, it's not recognized as a bootable drive at all by the bios, so I can't boot from it.
I don't get to the grub menu at all.
What I determined that somehow during my day yesterday I formatted the wrong partition containing my boot drive. Instead one of the external drives I was setting up. And in all the chaos of yesterday I did not notice my boot drive was basically empty for all intents and purposes
The solution would obviously be to get it to a proper state with grub-install etc.
However that failed to make my system bootable.

So now I'm installing 24.04, or if that is a disappointment back to a new 22.04

[sitethief]

I managed to get to the `grub-install` step for the empty boot drive and afterwards a successful `update-grub`
even then did not manage to fix it into a bootable installation.
I'm gonna install 24.04

[tea for one]

Line 131 - nvme0n1p1 ext4 a1d41f74-6d9f-4434-a197-6fe6e4c9266d 52eb99d3-d854-4dae-b852-151a250097a7 Michel VL Backup EFI System Partition

Your ESP has ext4 filesystem, it should FAT32
Did it somehow change?

You could try to copy the contents, reformat to FAT32 and restore the contents.

[sitethief]

Line 131 - nvme0n1p1 ext4 a1d41f74-6d9f-4434-a197-6fe6e4c9266d 52eb99d3-d854-4dae-b852-151a250097a7 Michel VL Backup EFI System Partition

Your ESP has ext4 filesystem, it should FAT32
Did it somehow change?

You could try to copy the contents, reformat to FAT32 and restore the contents.

Yeah, I determined I accidentally formatted it .

[tea for one]

Then, you now realise why your PC doesn't boot.
It would have been helpful if you mentioned this in your original post.

Do you have a backup of your original ESP?