A family of Microsoft word processing software products for creating web, email, and print documents.
Seems I posted too soon the issue has come back...for all Word and Excel files.... launching by double clicking, or Right-Click "OpenWith" on a file in Explorer or on Desktop, gives the "Not implemented" error dialogue box.
Doesn't matter if the file is blocked or unblocked in Properties.
And they all open correctly if opened from inside Word or Excel.
(Powerpoint files aren't showing this behaviour BTW, they will open on double click)