[Wedframe]

Elite_360_, one more problem what I found.
If inline attachment is NOT image, then again will be error 404 to this "image"(like on above screenshot). So... I made hybrid code from your, from vB and from my own code... what first check the extension of attachment:

PHP Code:

if ($post['attach'] > 0)
    {
        $attachments = $vbulletin->db->query_read("SELECT attachmentid, filename
                FROM " . TABLE_PREFIX . "attachment
                WHERE `contenttypeid` = 1 AND `userid` = " . $post['userid'] . "
                AND `state` = 'visible' AND `contentid` = " . $post['postid'] . "
        ");

        
        while ($attachments_info = $vbulletin->db->fetch_array($attachments))
        {
            $filename = strtolower($attachments_info['filename']);
            $extension = substr(strrchr($filename, '.'), 1);
            $extensions = array("jpg", "jpeg", "png", "gif");
            if (!in_array($extension, $extensions))
            {
                continue;
            }
            //Generate images instead links to inline attachment images
            $post['attach'] = 0; 
            $post['message'] = preg_replace("/<a href=\"(\w{4,5}:\/\/.*attachmentid\=" .$attachments_info['attachmentid']. ")\"\s(.|\n)*<\/a>/U", "<img style=\"max-width:" .$vbulletin->options['adv_printthread_images_size']. "; max-height:" .$vbulletin->options['adv_printthread_images_size']. ";" .$vbulletin->options['adv_printthread_images_style']. "\" src=\"\\1\">", $post['message']);
            
        }
    
    } 


And.... I release new mod with some more functionality(and it will be still more with time):
https://vborg.vbsupport.ru/showthrea...78#post2554078
I hope its not bad idea?