Today i installed compiz through gnome extensions to get the jelly mode Zorin comes with (Compiz windows effect - GNOME Shell Extensions). After switching wallpaper a few times my laptop froze. Could not do anything and had never freezing issues on this laptop so i uninstalled compiz and the gnome extension plugin in firefox.
CTRL + ALT + F1, login and good to go.
what does sudo apt install compiz-core do ? tried to install it it did not add anything new in extensions. So i used the command "compiz" in the terminal, couldnt load it said but i could try to use "compiz --replace" ... tried it and got a error and it logged me off. So signed in again and thankfully it shows my desktop (didnt test on my test driver) and uninstalled it haha.