Hi again Stefan. I gave up trying to find a solution so I just copied the entire document, pictures, graphics, styles and text and pasted it into Notepad which removed all formatting as well as everything else. I pasted that into a new Word docx and all is well for the last week. I can always add the pics later which is what I should have done from the beginning.

At least I now know that it was the document and not my Word installation that was at fault. Thanks for all your help.