You shouldn't need ijji to download the game. Not sure of the error your getting, but I downloaded and played successfully without needing/using ijji.
Yeah I was looking and I really have no idea. I don't even know what the ijji thing is... Try turning off your antivirus/restarting your computer. If that doesn't work try completely removing your current Tera from your computer if you still have it from the torrent. Then try uninstalling and reinsalling your Internet Explorer. If none of that works I don't know what to tell you. If you know what revouninstaller is I would recommend using that to completely remove the applications and such so you can start from scratch.
