Download the latest patch on the first page. Patch it and then walk in and out of a building so the patch changes can take affect. After that, there's a cave entrance on Huntik Route, go into it and you'll end up on Trident Waters. Which is above Millennium City. Your next step is to fly or get back to Tiki Village somehow or Fells Town. Go into Twistwoodlands and the gym is now open.