I’m wrting a paper using Endnote XI. I sent a library to my boss who is using Endnote 9.
He could not open the file in his Endnote 9.
How can I solve this problem without let my boss update his Endnote because he does not want to update to a newer version.
Endnote library files are (kind of) backward compatible between X, X1, and X2. Version 8 and 9 files are compatible each other, and readable by X and later, but not backward compatible.
The best way is to use Endnote Export style to export references in text format, and read it by version 9 using Endnote Import filter. Images and attachments are not exported, though.
He should be able to open your .enl file in EndNote 9, providing that you send him the DATA folder as well. He must have the .enl file and the DATA folder in the same folder on his computer. Then he should be able to open the .enl file normally.