I would suggest contacting support.
Reach someone who can help
Technical support
For help using EndNote
Monday – Friday, 9 a.m. – 8 p.m. Eastern (GMT -5)
+1-800-336-4474, press 4
http://ip-science.thomsonreuters.com/techsupport/
The other things to try would be to Recover your library or reset the EndNote preferences.
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