I am currently using the latest version of the Download Mod. For some reason, only Admins can upload thumbnails though. A regular user cannot. I am guessing this is a permissions problem. Is there anyone that can tell me what to change to let normal members upload thumbnails as well?
Look on ACP for all settings.
Enter a thumbnail filesize on the general download configuration and enable after this thumbnails on the wanted category.
After this, each user can upload them...