What happens is down to whichever viewer you are using for Word files.
If you have MS Office installed then you're probably using the Microsoft Word Preview Handler which comes with it, and you should see the same thing in Explorer's viewer in that case.
It's possible that you've installed something which has a different Word document viewer and has taken over from the Microsoft one. It'll say which you are using at the top of the preview pane, in brackets next to the filename.
I don't know how the different Word document viewers handle headers and footers so I can't comment on whether that is normal or not. None of it is our code or part of Opus.
Sorry, I missed that in your original post. (Not enough sleep .)
I'm not sure if reinstalling Word would change things. We're still not sure if this is new behaviour or how it has always behaved (or maybe due to how the files themselves were saved?). If it is to do with Word's configuration, I'm not sure that reinstalling Word would reset it (although it might).
If nobody here knows, it might be worth finding a forum of people who know a lot about Word and asking there, since it's the same in Explorer and not something Opus is doing.
I have the same problem (I believe since Win 8.1, but I'm not sure).
DO and Explorer doesn't show the header/footer in preview. I use Office 365 Home Premium.
What's the difference between the "App-V" and the "Microsoft Office" entries in the "Active X" Plugin? When I deactivate the "App-V" entries and leave "Microsoft Office" checked, docs are shown only binary. So what is the checked "Microsoft Office" doing?