Bookends Not Importing RIS Files

I recently tried to import a RIS file I had downloaded from JSTOR into Bookends (13.1.5). I selected the RIS filter in the dialogue box and clicked okay:

Screen Shot 2019 01 16 at 3 20 24 PM

But the RIS files are grayed out:

Screen Shot 2019 01 16 at 3 20 33 PM