We need more info:
* Verify exactly which DLCs are working and which are not. Do they show in the launcher?
* What OS are you using?
* Check your DLC installation folder (normally "Program Files/steam/steamapps/common/Crusader Kings II/DLC"). Do you have files there called dlc007.dlc, dlc007.zip (Sword of Islam)?
* If not, check the same in the folder "My Documents/Paradox Interactive/Crusader Kings II/DLC".
* Are you using a custom 'userdir'?
Also, please give us your logs (under "My Documents/Paradox Interactive/Crusader Kings II/logs")
* Verify exactly which DLCs are working and which are not. Do they show in the launcher?
* What OS are you using?
* Check your DLC installation folder (normally "Program Files/steam/steamapps/common/Crusader Kings II/DLC"). Do you have files there called dlc007.dlc, dlc007.zip (Sword of Islam)?
* If not, check the same in the folder "My Documents/Paradox Interactive/Crusader Kings II/DLC".
* Are you using a custom 'userdir'?
Also, please give us your logs (under "My Documents/Paradox Interactive/Crusader Kings II/logs")