My task involved to limit the number of downloads to 1 but with an exemption for those with a specific role or a so-called "credit". I've used hookdownloadauthorize() to try this one out. The first problem I encountered was that if you do a return FALSE as what the documentation mentioned, it would return the error "A hook denied your access to this file. Please contact the site administrator if this message has been received in error." based on this section of the code: <?php //Check any if any hook_download_authorize calls deny the download foreach (module_implements('download_authori...