[HMM IV TOURNAMENT ON] New Year's Olympic-Heroic Games

I would join, but I don't have the War of the Whirpools expansion.

What version of the game do you have? There's a way to patch it:)
Or, just go to the game folder and hover your mouse over the .exe file of the game. A window should appear with the version number (in numbers. War of the Whirpools is 3.0.0.2). Or, just go to the properties of this .exe file.