Most of the following information is based on personal experience, but it has not occurred for everyone in the same way, and because this is an apparent glitch, be aware that Zynga will move quickly to fix their error.
Move a chicken coop to the top right corner of your Farm in Farmville . Expand a storage shed completely, using the information found above, until the three stars in the storage area are yellow see below.
Under the capacity, it should also read "fully upgraded." Now refresh the farm and take a look inside the storage area. Additional chicken coops should appear. If they do, go to the coop and choose "move" and drag the coop. Another coop should appear.
If multiple chicken coops are the goal, try this soon before it is quickly fixed .
It is fixed by Zynga