Well. Be sure to click "View your MyTrainz Account" in the right top corner of https://www.auran.com/DLS/index.php, and edit "Country" to Germany in "Edit Account" section. If you don't change this, the default country is Australia (my case), even if you are in Germany in reality.
Just change the forum account profile location to Germany, which is what I did, and everything works fine. I have no idea why N3V provides download service according to the location of user profile.
Thank you oldman777. I tried changing my profile location to Germany and it works. The "Restricted" folder in FTP is back and all assets in CM are downloadable. I think the N3V provides download service according to the nationality of each account, which is really not equal to people around the...
Thanks oldman777. I have tried WinSCP through FTP protocol, but there's only a "pub" folder in the root path, no "Restricted" folder which I had seen a few days ago. I have also tried switching my IP address to the UK and the US and nothing works. Seems the DLS server is down. My First class...