Not working plantations (Assassin's Creed 4: Black Flag)

I have a new problem. Not raboyut plantation. When I go to the territory of the plantation, nothing happens. The person with the key there though the warehouse is full. Perhaps this is due to the fact that I had to replay the mission the harvest of sugar cane because at the time of the robbery plantation, the warehouse was empty. Just then a pen and began to work the plantation.