I tried several things to correct the issue, connecting to the recovery mode to try and repair things (I followed the repair process in this forum post), but nothing worked.
I also tried to create a new user in recovery mode, but the user also had the same issue.
My last test showed me something interesting : in the main login screen, I'm able to login by using the TTY (Ctrl + Alt + F2) and then launching startx.
Everything seems to work correctly, except I'm stuck with the MacOS disposition (I was using the "Windows 10" disposition).
And when trying to change Zorin's appearance with the Appareance tool, I have nothing in the Disposition menu.
Not appearing on the screen (because I closed the display) was an option telling me there were more dispositions available with Zorin Pro.
It seems that an update accidentally removed the list of available dispositions. Is that a known bug ? What should I do to get the default dispositions back ?
And if the above doesn't work, could you share the terminal output when reinstalling those packages, as well as the zorin-os-desktop? Maybe there's a warning or error message somewhere in there.
It's exactly like when I tried to create a new user from the root console in recovery mode : the error screen changed theme (reverting to the default white one) but the error remains.
I don't remember doing anything about a version update to do that. I just tried the commands since the error seemed close to the issue I had and I feared there was an automatic update in a half-finished status (which is not the case since I was able to verify later I was still on Core 17.3).
I just did what I always do when booting my computer, which is updating everything and go on for the day.
I finished the day with some experiments on adding an option on the file explorer's right click, but as I just added a file to ~/.local/share/nautilus/scripts, I doubt it had such an effect on the whole OS.
I do not see anything here that should have this kind of result. Yes, I know some will comment on autoremove, but the Zorin System is quite good about stable and correct dependencies, so I think we can set this aside.
This does have potential. Nautilus, as the File Manager, does a lot more integrated managing than just previewing files. And it is integrated with the Gnome Shell.
I had suggested looking in ~/.config, but maybe we need to check ~/.local
Okay, you wrote that it happened in the Morning. What did You before with it? Were there any Updates the Day before or before You have shut it down? Or did You installed any Programs?