Starting tonight I started to get random disconnects from the game with an error message saying...
"An error occurred"
...but no mention of what the error is. Very helpful. There was no crash dump produced and I was able to log back in every time without problems. Except that after another two or three games I'd be disconnected again.
First thing I did was run the repair tool. No joy. Second game in, another disconnect.
Next thing I tried was to update my drivers. Got a small bump in average frame rates (small win) but after another two or three games yet another disconnect.
Now everything worked fine yesterday when I played and I hadn't changed anything before the disconnects started to happen so I went looking for anything that might have changed automatically.
Bingo! (I think). "Avast" anti virus has updated to a newer version. Pretty sure this is the cause as it's the only thing I can find that has changed.
Avast program version = 2014.9.0.2013 and virus definitions = 140314-1
That's the good news (if you can call it that). The bad news is I haven't figured out how to stop it disconnecting me (other than deleting the program and switching to another anti-virus - we'll call that Plan B ).
I'm open to suggestions for a Plan A!
System specs in the spoiler below just in case they're important (or you're just nosey )...
Spoiler