Playing gods of old, I built a cottage on a grasslands with dye on it ( i don't have calendar yet) And on the turn the cottage was complete, the dye disappeared from the tile and the cottage appeared as a town. The mouse-over still displays the correct info (dye is present, cottage with 10 turns till hamlet) but the graphic is wrong. The save game and a screenshot are attached. In the screenshot, the tooltip is for the tile in the center with the worker on it.