> On the login screen after decrypting, when I clicked to choose Gnome, enter
my password, it would seem to load then crash back to the login screen.
It could be that something went wrong installing GNOME then. Hard to say
without troubleshooting.
> I removed MATE by going into terminal-fullscreen (I don't know the real
terminology for any of these I'm afraid) using CTRL ALT F1, sudo -i, apt
remove mate-*
It sounds like you removed MATE on purpose, perhaps because you expected it
to conflict with GNOME. It wouldn't though. If you want to have GNOME
installed alongside MATE, all you have to do is install GNOME and leave MATE
alone.
> terminal-fullscreen (I don't know the real terminology for any of these I'm
afraid)
The term is "TTY".
> then installed Gnome using apt install gnome gdm3.
If you want to use the GNOME desktop environment, you just need to install
"gnome". GDM is a display manager (the program that provides the login
screen) like LightDM (Trisquel's default). You should be able to use either
DM to log into any DE you have installed. On some distros GNOME might not
work perfectly without GDM (for example, on Hyperbola I fing that you cannot
lock your screen in GNOME unless you use GDM) but Ubuntu has patched LightDM
to work well with GNOME, and that's the version of LightDM that Trisquel
uses.
