Ubisoft DLC not compatible with Steam game?
I'm having the same issue. Just bought Season Pass on Ubisoft, and when I'm in-game and go to the store, it says Season Pass is installed and that I own The Hidden Ones and Curse of the Pharao, but when I scroll over those, it says left-click to download, which then opens Steam in a browser window. I can't download the content and instead am asked to purchase it.
I guess I'll now have to ask Ubisoft to return my money and then purchase Season Pass again on Steam? Never mind that Season Pass is more than twice as expensive on Steam.
This is extremely frustrating. There should be a warning to buyers of the DLC to make sure that they're buying it on the same platform as the original game or otherwise they may run into compatibility issues.