Alright my bad, there is a small bug that I just fixed and uploaded. In the MMM.xml file
Should be: <ImprovementType InternalName="K_NStables">
Instead of <ImprovementType InternalName="K_Stables">
because the information will clash with the existing data and the tile will cost and produce twice as much because of a bug in the way improvement data is saved. You can fix it manually or just download it again. Once again I apologize.