Hi, Kasper. This is an odd issue! If you are able to leave a Steam review then that implies that you do own the game on Steam. :) I do see that your Steam ID isn't currently linked to a Ubisoft account, and that could be the issue with starting the game. You will want to close Uplay and Steam entirely, install the latest version of Uplay PC[uplay.ubi.com], log into your Ubisoft account after restarting Uplay, and then launch the game from your Steam library after restarting Steam. Let me know in the comments if that helps!