Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - Technical Issues About some bugs for pre-order.

That is a known issue, which is being looked into, but has been difficult to reliably reproduce.

There is only one copy of the DLC for the duo pack / collector's edition. If you are playing co-op both people have access the DLC items, but there is only one instance of each item in the game (they are unique).