We've moved Terra (EU) off TCP Port 7778 and on to TCP Port 8394.
If this port is blocked by your Firewall / Router / ISP you'll need to unblock it. If you find you can't connect to Terra but you can connect to Zephyr (US-East) or Cleavius (Oceanic) it is because this port is being blocked on your connection.
This change has been made as a test, if it is successful all servers will be moving to TCP Port 8394 as it seems this port is far less likely to be blocked for some users.