Error message when trying to publish comments in Shared Review PDF

Hi,

I set up a PDF for shared review on a local server. (I'm using Adobe Acrobat Pro DC, the 2015 release). I thought I had set it up correctly, but when I try to publish my comments or check for new comments, it says "One or more files are missing on the server."

I am not sure what it means. I created a subfolder just for the review document, and when I set it up for shared review, it created an additional folder inside my subfolder. The additional folder contains an empty folder called attachments and an XML file which contains information about my comments. Should there be an additional file in that folder?

For now, I can work offline, but I would like to be able to publish comments and see other people's comments.