Editing the theme inside `gnome-shell-theme.gresource` prevented Ubuntu from starting

[tea for one]

And if you want to edit your login screen you can use [this script from thiggy01][1] instead of bricking your OS.

[1]: https://github.com/thiggy01/ubuntu-2...gdm-background

Thanks for the link - it's a good find

[blazking]

More specifically I changed what was under the #lockDialogGroup section. This prevented my laptop from booting.

Same here.
I installed ubuntu alongside win10 on a new laptop (asus g14), and as I wanted to change the login page I ended up editing the gnome-shell-theme.gresource file -in the Yaru theme folder- as I could not see any .css ones as in previous versions.
I then had a black screen when I wanted to log in (didnt "see" any error messages).
I re-edited the concerned file later on, putting the only value I changed back to its default one (under #lockDialogGroup). I paid attention to spaces and all...but I kept having a black screen on login.
From what I've read on this thread and others, 'seems like a bad idea to play w/ this file .

For other folks who would read this post later on, here's what I did to solve the issue in my case :

1. chose "Advanced options for Ubuntu" -> why ? Because you'll want to use the command line to fix the error.
2. make sure you "Enable networking" (I had a rj45 cable plugged into a usb-c adapter, glad this one worked smoothly ).
3. chose "Drop to root shell prompt" -> why ? to load a shell prompt as root
4. As explained above, editing the file back to its original version did not seem to work (didnt look "why" yet, but I'd be curious to understand as I'm pretty sure I had correctly edited the file back to its original version).
So from here I did the following :
a) switched back to my user from root (su your_user), as I was not sure if there was any "context awareness" regarding this theme "thing".
b) Then, I simply re-installed the Yaru theme package (similarly as proposed in OP post here : https://ubuntuforums.org/showthread....8#post13982398 ) but with the following : sudo apt-get install --reinstall gnome-shell-extensions yaru-theme-gnome-shell

I'm now back to my "purple-ish" login.