glass stuck in mold

[betnca]

I just took a project out of the kiln and it was stuck in the mold. I used MR 97 Boron Nitride according to directions on a Patty Gray 6″ square mold. I fired it to 1500 and held for 20 min. Then followed Bullseye schedule for cooling. Several things happened 1) the stacked glass did not flow to fill the mold 2) the glass cracked internally during cooling 3) it stuck to the mold BUT I love the color combination. I just put it in the freezer and am hoping for the best.