You might have an old import filter. Check the EndNote page to see if there is a more recent one available.
If not, be sure you used a compatible format when you saved or emailed your list of references or citation results. Each of the fields in your output should have a label that can be recognized by the filter (e.g., AU: or AU- or Author:).
For additional help with EndNote at Virginia Tech's University Libraries, contact endnote-support-g@vt.edu. Please include a detailed description of the problem you're experiencing, as well as any screenshots of the error.
EndNote has an extensive user support system, including technical support, a user community, and a knowledge base. Visit http://endnote.com/support for a variety of support options.