When try to join in a 'The Conqueror' game, it shows this. But it doesn`t happen when I join a game of 'The Age of Kings' ... what to do ?

Network Connection Error [Code: 50000000]. Connection errors are typically caused by a temporary server outage, a firewall, or a problem with your internet connection. If it's been a long time since you've connected to Voobly it's recommended that you redownload the client from the website.

Check this http://www.voobly.com/forum/thread/245293