Doh ! Spoke too soon. Immediately after that last post I went to my inbox and clicked on the link to reply to a post about clean motorhomes and got the Read ssl. gstatic. com message again and a blank screen.
I've read Jean-Luc's link above but, to be honest, don't actually understand a lot of it and am not sure what to do to apply any fix to my computer. My computer has been advising me about a Java update for ages now which I have resisted as last time it bunged everything up, but perhaps that might help.
Will give it a try....