Galley PDF does not display in for a single Volume

I have a journal (on OJS that only with the latest volume published all of a sudden is experiencing a problem with showing the PDF document in the article view mode. I checked the community forum and have made sure that the file permissons is set correctly under files_dir. The file permissions of the PDFs for the latest volume is exactly the same as for previous volumes, but they don’t display. All paths are correct as well.

The only difference I see in how OJS is behaving with the latest volume is that in the “$article && $galley” statement is true when the download function is called. With the previous volumes this does not seem to be the case.

* Downloads the document
* @param $args array
* @param $request Request
function download($args, &$request) {
$articleId = isset($args[0]) ? $args[0] : 0;
$galleyId = isset($args[1]) ? $args[1] : 0;
$this->validate($request, $articleId, $galleyId);
$journal =& $this->journal;
$issue =& $this->issue;
$article =& $this->article;

            $galleyDao =& DAORegistry::getDAO('ArticleGalleyDAO');
            if ($journal->getSetting('enablePublicGalleyId')) {
                    $galley =& $galleyDao->getGalleyByBestGalleyId($galleyId, $article->getId());
            } else {
                    $galley =& $galleyDao->getGalley($galleyId, $article->getId());

            if ($article && $galley) {
                    $fileId = $galley->getFileId();
                    if (!HookRegistry::call('ArticleHandler::downloadFile', array(&$article, &$galley, &$fileId))) {
                            $articleFileManager = new ArticleFileManager($article->getId());

Even so no errors come up in my Apache2 error logs. Is it possible that something went wrong after the galleys were created?