I was getting this error message when I tried to open a document in Word 2003: “This document could not be registered. It will not be possible to create links from other documents to this document.”
Word still worked but I was unable to drag-and-drop content. And Outlook would not let me use Word as the editor for my email (which is perhaps an evil thing to do anyway).
Turns out the problem was that a service was not starting automatically (DCOM Server Process Launcher). I don’t recall making that change but that’s beside the point. The point is that the error message is terrible. It is disrespectful to the user because it hints at an underlying problem but does not give you any guidance on how to fix it. Sadly, disrespectful error messages are much too common.