why can't I duplicate a project in iPhoto?

Hi,

I am wondering if you can help me. I have been trying to duplicate a current photo album I created past month on my mac, but when I do it, there are not photos in there. 😐

Do you know if there is a problem? Am I missing something?

I have the newest system version: macOS High Sierra 10.13.3

Thanks in advance for any help!

Sandra