"No available formats"

I recently tried adding a book to calibre--the book appears to have been added, though without any metadata--and when I tried to open it I get an error message saying that the book has no available formats. I'm able to open the book directly from the folder I downloaded it to, but calibre can't seem to find it. I added 7 books from the same vendor at the same time without issues. I thought it might be a problem with the file, but the vendor emailed me the file directly and I'm having the same problem.

I'm running Linux Mint 17.3. The only apparent error message I get when I open calibre in the terminal is about not finding the cover jpg.