Renamed library not matching date files

I have a library patron who had two EndNote (X7) libraries saved in her documents folder. One was robust, with more than 100 referenbces, while the other had just a few. She wanted to keep the larger library and delete the smaller one.  She renamied both, and moved them into another folder within her Documents folder.  Now when she opens EndNote, she can only access the smaller library. 

I’m guessing there was some problem with renaming and changing th pathways, and maybe something about the library and i’s associated data file being uncoupled?

Does anyone have any idea what I’m talking about (because I’m not sure that I do), and what to do about it?