Can't start any Sarajevo Six missions

Unable to start any of the missions for the Sarajevo Six side campaign. Just keep getting an error. No issue starting any other missions. Just specifically Sarajevo Six missions. I’m on PC using Steam.

Oh well I think I figured out the issue. I had not purchased the DLC yet. I started the game and while running the game I chose to buy the DLC. The purchase went through and it then let me try starting the missions but it would keep giving that error. I just needed to restart my game and now it works fine.