I’m using Google App Engine to host my site. The pdfs are in my root folder, which gets uploaded when I deploy. I’m hosting images on my site in the same way and they work fine. I’m wondering if it must be something with Google App engine, though I can’t imagine why it wouldn’t work. Hopefully I can get this to work, but in the meantime I’m probably going to have to just upload the pdfs somewhere else and link to them that way.