Setting 'vt=7' in the '[seat-0]' portion of '/etc/lightdm/lightdm.conf' seems to have stopped the crashing (which I got from time to time - NOT always - using the '2' and 'Enter' key).
Setting 'vt=7' in the '[seat-0]' portion of '/etc/lightdm/ lightdm. conf' seems to have stopped the crashing (which I got from time to time - NOT always - using the '2' and 'Enter' key).