I have played the ultimate edition with all dlc and extra campaigns for over hundered of hours with no problem. A few days ago i stared the game up again and all dlc was missing and all the extra campaigns too, i tried reinstalling it but it didn't work. please help.

only thing i can think of is maybe your antivirus got a false positive on it and deleted it for you
you should check the logs

if that is what happend just add the game to the antivirus' whitelist