solution:
Download the program Spotflux. This is a VPN client that masks your IP. For the lazy, download link here
http://download.cnet.com/Spotflux/3000-2092_4-75762054.html Install Spotflux
Open Spotflux. On the top left corner, click the little tool icon (Settings)
Click on the Filters tab, and click "VPN-only mode"
Click the OK button
Open your TERA Launcher