I uploaded a PDF without a problem (1.5 mb)
When I tried to upload a .mobi file,(4 mb) it appears to upload, shows the correct file size at the bottom. when I click publish, the following error appears on the screen.
The file does not exist! Please check the URL and ensure it is within the WordPress directory structure. (For example: http://idolbuster.com/wp-content/uploads/delightful-downloads)