error: "the range cannot be deleted"

Dear all, 

I’m using endnote for my thesis. However, since this afternoon I keep getting the error message “the range cannot be deleted” when I try to insert a new endnote reference in my word document. I tried googling a solution but haven’t found any. Hopefully someone here can help me how the identify and solve the problem? 

Any help is much appreciated! 

Have you tried making a copy and accepting all tracked changes?  Sometimes this occurs with tracked changes, especially if they are showing.  

Nope, there were no tracked changes made to the document.

Try the steps in this KB article?