Problem adding new citations to document with existing bibliography

I have been working on a document that has a little over 200 citations now and everything has been going well up until today.  Now, for some reason, whenever I try to add a new citation to my document, by bibliography suddenly loses about 150 of its references.  I’ve tried working with previous versions of the library (saved as a backup), but this does not seem to fix the problem.  It doesn’t seem to matter if I am adding a citation for something that is already in my library or if I am adding a new reference to my library.  I notice that a lot of the in-text citations (which are marked by numbers) are no longer linked to the reference list after this happens and that clicking on them causes my cursor to jump to the beginning of the document.  

Any helpful suggestions would be greatly appreciated.  

This sounds serious enough to skip the forum and go to tech support.  - by phone.  Please remember to tell  them which versions of Word and Endnote you are using and the operating system.  (and tell the forum too).