RHEL 7.4 - Recover broken desktop GUI

Hi,
I have a fresh install of redhat 7.4-64bit on an Intel based system.

I've managed to corrupt the Gnome interface and ideally want to restore the defaults, like mentioned in this article under "reconfiguring the X server configuration":
[Fix graphical display issues] (https://access.redhat.com/solutions/5338)

How do I do that in RHEL 7?
Thanks in advance!

Symptoms:
When I run "startx" from the command line, it hangs for a moment, then I get a message to check the Xorg log and "serverauth.1845 does not exist."
There are no errors in Xorg log.
Background:
I originally installed the "Server with GUI" package. Then changed my mind, did a 'yum group remove' and installed "GNOME Desktop".