My kingdom just finished a war, and I have noticed a bug that works in my favor. It says I have "20 building credits left" but I can build as many buildings as I want, and it doesn't charge me anything. I've tested this multiple times today. Since age is about to change, seems a good time to look into this and fix it. My province is The King Made Water Wine (5:15) if you need to see details with why this is happening.