Library deleted / not working. Is there any help?

Solution:

Fortunately, EndNote has a built-in «backup» option.

If you should have deleted the base and do not have access to a backup, there is still a possibility. For each EndNote library, a file (such as «test.enl») is created with an associated directory (such as «test.Data»).
Create a blank text file without any formatting (for example, using the Notepad program) and call it the deleted file.
Then open the empty text file in EndNote and the program will try to rebuild the base based on the data in the associated folder.
(If the folder should also be deleted / damaged, this method will not proceed.)

If you have the base but are told that there is something fundamentally wrong with it, the easiest way is to use the «Recover Library» command under the «Tools» menu. (Make a copy of your base before doing this.) Note that the reference numbers – which scroll. used in the link between Word document and the EndNote library – will change when you use this command.