TeleportService won't work in my game?

I'm trying to make this lobby system in my game, and I made a new game inside of the starting place. When I tried to make a teleporting brick to the second game, I tested it in Roblox and when I step on the teleport brick, Roblox will always crash, no matter the method of scripting I use for the teleport brick. It seems that if I put the GameID of the second game, it always crashes Roblox, but when I put the GameID of the starting place, it works fine (it makes you re-join). Any idea on what's happening? (I've tried making the two games public, and double-checking the ID as well)