Endnote X7 Word Plugin

I have been using the MS Word plugin of Endnote to easily insert citations in my text as I write. As of now, I use the MHRA (Author-Date) style, so that the authors appear as follows: (Author, 2017). I regularly send my documents to colleagues to review. When they send the file with tracked changes back to me, something strange occurs: when I try to insert citations, the citation will appear as follows: {Author, 2017 #185}

Of course, this is not acceptable. Additionally, the new entry is not included in the automatically generated bibliography.

Does anyone have any pointers as to how I could solve this problem?

If they have Endnote, they might turn off auto formating and when you get it back that setting is retained. (or if they don’t have endnote that might happen automatically, as word doesn’t know what those fields represent.)  What you are seeing is the “temporary” or unformatted endnote citation.  You can turn on Auto formatting from the endnote ribbon (see image) and make sure the output style you selected, is still on the ribbon as well.  

But there is another dangerous thing that might happen.  If they open it and somehow erase the endnote fields and turn them into plain text, they you might lose all the automatic features of endnote’s fields.  You can tell by turning back on autoformating or choosing the update citations and bibliography and that citation will be formated and if it is inserted in the proper place in the existing bibliography - you are good to go.  If it begins a new bibliography, you are in trouble.  Also, if the fields are retained, the bibliography should be “grey” when you put your cursor in it as should an inserted citation, when your cursor is in it.  

If a colleague for example opens the word document in OpenOffice - that will corrupt the Word/Endnote inserted fields.  

You are far safer sharing the document in that curly bracketed state, as they are unlikely to get corrupted and you can update it when it  is back in your hands, unless you know your colleagues are using the same software and use or understand Endnote field usage.