Thanks for your help.
I've run the above Fix-it link in normal mode (no change) and aggressively mode (again, no change). Rebooted immediately after aggressive run but, again, no change. The white flag with red circle and a cross in it still exists as does the error as shown in my first screen capture. The Fix-it link says it repaired both times, attached is a screen shot after the aggressive run of Fix-it.
I then adjusted the automatic update time to see if an automatic update would run normally, but for some reason it did not do it, possibly because it had already run today. So although that particular automatic update did not run as planned, I am confident that THEY DO RUN, as the history of the updates shows.
It's a strange little problem this. I have searched the internet for a solution, but other than vaque references and a complete re-install type solution, I have not found a lot.
Where to now?? Is it more effort than it's worth, do you think?
David