SOFTWARE/OS VERSIONS
Windows: Windows 10 Pro
macOS: 
Linux/KDE Plasma: Latest offline update as of 28-4-2021 (today)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

System specs:
Lenovo W520 SSD (neon) + HDD (win10)

Stuck on grub, no matter what input it just sits there. Hitting left/right arrow key makes grub boot menu go blank. Booting windows also doesn't work.

Not using LUKS, besides would expect windows to normally load if it was a luks issue.

Booting from a live usb stick using the following (in my case)

ls (hd1,msdos8)/
set root=(hd1,gpt1)
set prefix=(hd1,gpt2)/efi/neon/
insmod linux
insmod normal
normal

Displayed my normal grub boot menu. Using that im back in KDE neon. Using a update-grub and rebooting does not fix it.

turns out my /boot directory was empty after that update. after booting from a neon live cd and running boot-repair i was able to successfully boot back into my main, encrypted neon install.

eek

A grub issue if you ask me, my boot files were fine though. Why it failed and a update-grub didn't work I can't tell. reinstalling grub fixed it, but i did not check and verify grub version numbers. Again a update-grub only did not solve the issue so i guess there's a different version.

just had this happen again to me after the 5.21.5 updates that rolled through today 😭

i have an idea why this might be happening to me. a while back, before the offline updates were introduced, i was having to manually clear out older kernels because it wasnt being done and i kept getting errors in discover about running out of space when there were updates to install newer kernels. i just manually purged the old ones because i didnt want to reinstall the os or fix whatever the issue was by resizing things and possibly permanently breaking something.

now that the offline updates are are thing i think this issue is happening but its uglier because its during boot and fails in an uglier way. i dont know why its leaving /boot empty, though.

here is my current kernel list:

$ dpkg --list | egrep -i --color 'linux-image|linux-headers|linux-modules' | awk '{ print $2 }'
linux-headers-5.4.0-72
linux-headers-5.4.0-72-generic
linux-headers-5.8.0-45-generic
linux-headers-5.8.0-48-generic
linux-headers-5.8.0-49-generic
linux-headers-5.8.0-50-generic
linux-headers-generic
linux-headers-generic-hwe-20.04
linux-image-5.8.0-45-generic
linux-image-5.8.0-48-generic
linux-image-5.8.0-49-generic
linux-image-5.8.0-50-generic
linux-image-generic-hwe-20.04
linux-modules-5.8.0-45-generic
linux-modules-5.8.0-48-generic
linux-modules-5.8.0-49-generic
linux-modules-5.8.0-50-generic
linux-modules-extra-5.8.0-45-generic
linux-modules-extra-5.8.0-48-generic
linux-modules-extra-5.8.0-49-generic
linux-modules-extra-5.8.0-50-generic

(In reply to kinghat from comment #6)
> just had this happen again to me after the 5.21.5 updates that rolled
> through today 😭

Same again here too 😭😭😭

i removed all of my older kernels to test my theory about there not being enough room for more kernels during the update process, and somehow leaving my /boot dir empty, was partially confirmed with the recent 5.8.0-53-generic update. the update went fine 🤷‍♂️

I also had an issue with getting only a black screen after selecting neon from efi prompt after an offline update. In my case, I was able to boot off the neon live usb environment, install repair-boot, and run it to fix whatever was messed up in the efi/grub setup.

Marking as duplicate. Please change the status if you can reproduce the issue with discover >= 5.26.

*** This bug has been marked as a duplicate of bug 457868 ***