Please check the version of Reference Manager you are using. In Reference Manager go to Help > About Reference Manager 12. If you have 12 and not 12.0.3 you should try getting the update.
Please see our website for the steps to update the Network version of Reference Manager:
http://www.refman.com/support/rm1203update.asp
If you have the update installed and are still having trouble then:
It is possible that your document has corrupt field codes in it. We have a FAQ on our web site that gives the steps to remove all of the field codes and clean up the document. You should first make a backup of your Word document and then follow the steps in the FAQ at:
http://www.refman.com/support/faqs/CWYW/faq6.asp
Let us know if you have any questions or if this does not resolve the issue.