Sometimes EndNote will not download a PDF, although at PDF is available.
When that happens, you can still retrieve the PDF.
1) Select Reference / URL / Open URL or Command + G
2) This will take you back to the citation (except for Google Scholar), where you can locate and download
the citation. Download it to a folder you can locate.
3) After you have downloaded the PDF, you can manually attach the PDF to your citation. (See the next tab for instructions).