I was just mucking about in xfce, trying out new window buttons in conjunction with the black theme - dusk?? - when POW! - X shut down. Rebooting didn't restore things. Error is along these lines:

xfce4-session: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
xfwm4: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.0.
(xfce4-settings-helper: 2134): libxfcegui4-WARNING **: ICE I/O Error
(xfce4-settings-helper:2134): libxfcegui4-WARNING ** Disconnected from session manager
Thunar: Fatal error 11 (Resource temporarily unavailable) on X server :0.0.
xfce4-panel: Fatal IO error 104 (Connection reset by peer) on X server :0.0.
Agent pid 2036 killed
xinit: connection to X sertver lost
waiting for X server to shut down xfce4-settings-helper: Fatal IO error 104 (Connection reset by peer) on X server :0.0.

Is there a config file I can edit to get away from the window button setting it dislikes, or is reinstalling xfce the only option?
P.S: I'm back on 13.1.

You could just remove/rename the xfce4 folder. Should be at /home/user_name/.config/xfce4. Then a restart should put you back to the software default settings.

Yes, that did the trick
I was pretty sure it would be as simple as that, just wanted to make sure. Never had xfce do that before :/