[xubuntu-users] Failed upgrade

[Tim]

I had xubuntu 10.04lts which I upgraded to 12.04 lts. The server was set 
to boot to cli and then startx if I needed a gui. Now when I type startx 
and press return a couple of seconds later a small box appears in the 
middle of the screen with a large red no entry sign and the words Failed 
to load session "gnome"  the only option is to click a button that says 
log out.

Can anybody please advise

Tim