Hanging at password entry after upgrade

[torreydale]

Jerry beat me to this and is correct. 

If you created a Systemback restore point, use it.  If not, reinstall Linux Lite.  Avoid installing the Ubuntu updater, manually run updates from now on (Menu > Favorites > Install Updates), and use Systemback to create restore points.

[Jerry]

Sounds like you have pulled in the Ubuntu updater at some point. This will be what is notifying you.

Sent from my Nexus 6 using Tapatalk

[frank4360]

You say it is well documented, but at every software update the system says that 16.04 is available and asked if I wanted to upgrade. Finally I agreed, and the result is an unbootable system.

[Jerry]

There is no upgrade path from a 14.04 to 16.04 base in Linux Lite. This is well documented and will most certainly lead to system breakage.

Sent from my Nexus 6 using Tapatalk

[frank4360]

I have just run the upgrade from 14.04 to 16.04 - there were several System Program failures and at the end a screen showed that the upgrade had failed. However the system is indeed 16.04.1 LTS even though several packages were missing (Gparted, Pulse Audio, etc)
But at the first attempt to boot up the system I enter my password and nothing happens -  simply the "Logging in ..." mention.

How can I break into a terminal from this screen? Or force the system into some sort of life. All the alternative boot entries are 16.04.1 so I can't go back to 14.04.

Any ideas?

Thanks in advance.