Apr 6, 2016, 14:3004/06/16
Greetings m'lord
You're correct, you should be able to build up to 3 Warehouses and Barns. Make sure nothing is in their way! If you build the Warehouse on a place where something is already built, it obviously will not work! Check if you have the sufficient amount of resources for constructing it too.
If nothing of these things work and the issue persists, please contact the Help Desk.
Good luck!