Player doesn't teleport to world

Hey guys, I'm working on a mini-game.
I have had two test worlds that you could teleport to by joining the game related to the world.
I'm now adding some more games (and worlds) but for some reason the plugin won't teleport players into the world. They just stay in the lobby where the join-sign is.

What are the reasons that a player wouldn't be teleported to a world?
I have no errors in console.

 

If you put your code in, or at least some of it, we could help you much easier

 

If the world you are trying to teleport players to is unloaded for some reason, it won't work.
Also, is the sign on the wall or on a post? When you are checking if the block is a sign, you have to check for both the wall sign and the sign on a post.