"Object has been deleted"

Using Word 2003, EndNote X4, modified Chicago 16 style.

When i insert a reference in a footnote, it inserts,  but i get a message accompanied by a yellow triangle saying “object has been deleted”.

My only option is to click “OK”, though I really don’t know what i’m saying OK to.

There’s no information in the help file.

I have deleted a couple of duplicate entries recently

Any thoughts?

In this thread this error was associated with an incompatible footnote that pre-existed in the template used.  In another thread here, the problem was solved by unformating, cleaning up any fields with the CTRL+SHIFT+F9 (both in footnotes and in the document) and copying all the text apart from the last paragraph and creating a new document. 

See this FAQ for more details on cleaning up the codes in a document.  The phenotype described in this FAQ is different, but the fix is the same.