It doesn't seem to work through Steam. Try using the NDLAUNCHER.EXE file instead. Works for me, but then i'm stuck at the login in-game... Can't seem to connect to a server and also i'm supposed to use my email as account login but you can't even input an "@" so idk how to get in :/
I had the same problem and did this. Search for ndlauncher. I found it in this folder C:/programfiles(x86)/steam/steamapps/common/9dragons . When you find the app right click on it and create shortcut. Drag it onto your desktop. When there right click on it and Run as administrator. My game starts fine with this shortcut and run as admin after that.