Are you launching your tak from the tak switcher? If you are hosting, you don't click --->launch tak<---, that's only for people who are joining your ip game.
If you are hosting, you need to go to multiplayer/host network game inside the tak switcher.
People who are joining the ip game, they don't go to play an opponent by opening the tak.exe. They need to launch tak switcher and have the mod selected, and then click --->launch tak<---. Once they are in the game, they go to play an opponent. Make sure before you are hosting or joining the ip game to have the mod selected at the left panel of the switcher.
When you go to
www.ipchicken.com, you will see your external ip number; that's what you need to give the players that are joining the game.
Also, make sure to have your friends join where it says ---->launch tak<---- at the top of the switcher. They don't join the same way you host the game by going to multiplayer/host network game. Again, they only select the mod, and they click ---->launch tak<----. Then they put your ip in the "play an opponent" screen once they are inside the game.
Everything is clear on the .txt file, so there shouldn't be a problem,
Good luck.