For the record and if it helps diagnose this. I first niticed it when I posted the 'oops' thread in the 'computer room' at about 2am (i know
).
When I tried to open threads that showed 'new' posts I got the database error I posted earlier.
Threads with no new posts open OK hence I was able to start the 'Oops' thread.
When I tried this morning I could see no threads at all.