It was very likely that there was a problem with the game server that required maintenance. If you can't enter the game after trying many times, it might be because the game server is being updated or maintained, causing the game to not run normally. If you really like to play a game, you can try to see if it works on other computers or contact the game's customer service for help. They might tell you that you need to wait for a while before the game server can resume normal operations.