will not appears when you download a lot of link.You have reached the download-limit for free-users.
Get your own Premium-account now!
(Or wait 17 minutes, 21 seconds)
1. open all link that you want to download into tab (if supported)
2. input all captcha that shown in all tab and create a download link. But you don't do download it, but save the link into download manager.
3. after all download link have been saved in download manager, then start all download.
now you can download as many link as you want like premium user by using free user.
i think there is a bug in download system.