Hello,
I believe I have noticed a bug with the marble to stone feature at the provision house. If I make 50 marble from 250 stone, it works. But if I make three 50 sets of marble from 750 stone, I get nothing. I tried this for a number of days thinking it was my mistake but after the last time, I now can see it is a bug with the game. Thank you for your time and effort with this matter.