To create a new EndNote library:
To avoid unnecessary complications and corruption of your library, we strongly recommend that you have only one EndNote library.
When you create an EndNote Library this will create two files: a .enl (EndNote Library) file and a .data folder. It is important that both of these remain together in the same location and that they use the same name. Your EndNote Library won't work if the data folder is deleted or separated from the .enl file.
Spend 90 seconds learning how to create and then set up your EndNote library for full functionality.