Sorry to be so long getting back about this.
I tried someof the above, but without luck. With my limited abilities, I reckoned it was far too likely I would cause more problems if I tried to follow the others without really knowing what I am doing.
However, I found that I don’t have the problem if I just use Firefox instead of Internet Explorer.
Incidentally, if I click and highlight the page, you can see the text, though it is formatted as per the HTML page.
Anyway, I am going to use Firefox for the timebeing.
Thanks both for your help.
Mat