Recently, presumably upon an update to Word 2016, the following phenomenon started.
I usually open documents from Explorer or "Recent" on the taskbar.
Until a few weeks ago, files would open within the same instance of Word, whether it was already running or not. This remains the case with Excel, PowerPoint and other programs. But no longer with Word. Every file opens in a separate instance. If I open three files together, three new instances of Word begin. When I close a file, I need to exit the instance too. The only way to open a file in the same instance is Alt-F, O and then a laborious clicking process through directory folders to find the most recent version of each file. By which time I have probably lost my train of thought.


Since I have a relatively new and clean Windows and Office installation, I was expecting to see that other users had encountered and reported the same issue. But a Google search does not show any remedy for the issue. Hence this post.
I would assume that some Registry setting needs to be edited to return to normal.
Can anyone suggest a fix?