Tom - Many thanks for your help.
Here are two screen shots:
1) the "What's New" message comes up each time on opening, as if it were the first time.
There's nothing on the FCPX screen - it won't locate libraries.
2) There are nobackups
It is possible to import media but the system won't save edits - there is nothing there on restart.
A possible clue - the desktop began to act strangely earlier in the day - items missing from the dock and
desktop icons very large and in random places. After correction the problem recurs on restart.
Tried resetting VRAM to no avail.
I'c completely new to all of this so any help would be very much appreciated