Hello Everyone,
Just upgraded from version 2.4 to 3 and now for the published issues, we cannot download any PDF files. If we click on PDF on any published issue article, the link goes blank. Take example of this article.
Make sure you setup the file location in config.inc.php
If you want to upgrade to version 3.2 you can do it directly to that version, but if you want to upgrade to 3.1x you better upgrade to version 3.0. because based on my experience, if you upgrade directly to 3.1 from 2.xx you will get some errors.