Thanks Sanjit!
I've installed the new version, and pleased to report that the links on the left of my site are now working correctly.
Unfortunately there is still a problem.
The "The Dracula Society" header at the top of all the pages is on a master page, and it has a grey bevelled edge on the image frame which is swung to 90 degrees so it only appears at the bottom of the frame.
It now seems on the preview that it's appearing at the sides too, which isn't right.
It didn't look like that on version 2014.2.
It doesn't look like that on the page design screen, only on the preview, and I don't want to upload because I suspect it will look like that on the published version too.
I've tried adjusting it, but I can't now get it to look right, which is not at all helped by the fact that it doesn't look the same on the design page as it does on the preview page!
Any ideas?