Messed up big time, but ...

[Qqmike]

half my Kubuntu was GONE!!

Ha! I can just imagine your dismay. I read posts from users who do such things and wonder to myself, How the H&^l can THAT happen? Now I know!

[jglen490]

Been there. I once started a recursive Delete on a backup disk for some specific sub-directory set, hit the Go button, and got distracted with some sports on TV. Some minutes later, the blasted delete was still running and half my Kubuntu was GONE!! I learned from that moment on to ALWAYS reference the fully qualified path starting with "~", and not just some specific directory name. $PATH told the Delete to start from the beginning and most definitely not from the beginning of the directory that was on the mount point of the backup drive

[Qqmike]

First thing I thought of when I screwed up was a hobby interest I am working on: Korean grammar. When I use the word "Korean," you may think "Mathematics" (which I have a post-Master's in).
Korean grammar is mathematics in-drag. It is that difficult, a 'Level 4' language, 7-8 yrs in learning to be professionally fluent (according to US State Dept/Foreign Service).
I had been studying profusely with ChatGPT, really making great progress, and collecting a ton of material I copied (into Libre Writer) to study and review.
Fortunately, I make on-the-fly back-ups (to flash drives). Didn't lose a single verb conjugation!

I was on a first beer when I DELETED MY EFI, wth ...

[Schwarzer Kater]

This certainly could make somebody smile…

[Snowhog]

have a glas of wine and listen to some badlands-music

https://www.youtube.com/watch?v=UZ-gTdR3oTQ

[Qqmike]

@ S-K, the glass of wine would certainly help in these situations. 👍

[jlittle]

I hate UUIDs, I avoid them where possible.

[Qqmike]

Darn. And somehow from that black 'emergency' screen, I probably could have gotten a console and did that. Would have been easy after doing sudo grub-install while in the OS. Thanks.

[Qqmike]

Boy, I'm gonna have more empathy for users who post similar bizarre acts of liberty!

[Schwarzer Kater]

If you accidentally deleted and reformated your EFI partition ("/boot/efi") its UUID has changed!
You will have to enter the UUID of the newly formated EFI in the line with "/boot/efi" in your /etc/fstab accordingly…

PS: You can get the UUIDs with lsblk -f -e7.

PPS: And just switch off the computer for a while, have a glas of wine and listen to some badlands-music before switching it on again today, perhaps…

[Snowhog]

Well, one could say that's what you get for live'n in the badlands.

[Qqmike]

... I fixed it and don't know why my "fix" didn't work.
Long story ... got too much on my mind ... plugged in a 32 GB flash drive to reformat it as Fat32 ... wasn't focusing on my GParted ... DELETED MY EFI PARTITION on my main /dev/sda!!! WTH!

I tried to fix it:
Made a new EFI partition with boot efi flag (in that same unallocated space from my screw-up).
Did sudo grub-install (after mounting the EFI at /boot/efi).
Backed up my /home and bookmarks and T-Bird profile, etc.
Re-booted to an black screen 'emergency' notice with some options.
Didn't have any luck with the options offered (probably b/c I didn't really try to make anything work).

Re-booted to my Kubuntu live flash drive installer and re-installed the operating system.

Don't know why the grub-install didn't do the trick. I did, though, flash my PC's BIOS with an updated BIOS/UEFI file a couple weeks ago.
I did look into my /boot/efi and everything looked ok -- it was all there, all the /ubuntu/ boot files.

What a strange ending to an already hectic day.

(... and THEN ... I messed up my panel and taskbar ... which 'we' fixed in another thread just now ...)