Not sure that any of this will help but it might?
On the top Command Line there is a heading called 'View'. This will give three options:
I always use 'Page Width' as bigger and easier to read for my old eyes.
If the above does not help, go into 'Page Layout' (also on the top Command Line)where you will find a setting for the top, bottom, LH and RH page margins. Fiddling these might help. The default is, I think, 25.4 mm (one inch) all round.
Go to the menu for View and make sure that Ruler is On. This will allow you to see at the top of the page where the margins are set to. I have included an attachment to show the standard margin setup, named: Screen Shot 2019-10-11 at 07.46.15
Another thing to look at is whether you have more than one column set up. Go to the menu for Format and choose Columns. Make sure that the Presets are set to One. I have attached another screenshot showing this: Screen Shot 2019-10-11 at 07.54.07
It sounds to me that you might have the columns set up so you have two columns with one set off on the right, or left wherever you are getting the blank area. Either than or the margins are offset.
October? I wonder if this is not just co-incidental. I have just been successfully encourage to make latest update to Win 10 (1809 build 17763.805).
I use eM Client for EMAIL, MS having abandoned the entirely adequate Livemail. Immediately on restart I find eM Client is now trying to send (SMTP) via the IMAP server (as my EMail service, Enterprise.net moved off the Island I cannot use it for my internet connection so it refuses to accept mail which because of that appeared relayed from another domain). Don't see that as coincident.
Sorry to say none of the suggestions sent worked, but I have solved it myself, well in a way.
Open do***ent up & go to Review, then Simple Mark Up, then No Markup, hey presto the offending "Administrator" space vanishes.
It can then be viewed, worked on or printed as normal. Snag is, if saved back comes the original problem, I even tried to cut and paste leaving out the Administrator bit into a blank word do***ent & up the problem comes.
Giving it a new name and saving it without the Administrator bit still makes no difference. I give up.