There are a few reasons that icing may crack here are some of the main reasons: 1. The treat, itself was already cracked or it cracked under the icing after a few days. The icing will not officially cover cracks in treats, it will follow the crack over a few days. 2. The icing and frosting formulas are not meant to be used together or it will crack. For example... if you frost a cake with Rockin Hard Frosting and use Original Icing on top to write "Happy Birthday" - around the letters cracks will form. 3. The products are meant to be used, if you purchase 50 - 100 lbs you should use the product in @ 3 - 4 months. There is an expiration date inside each box, even if it expires in a year it needs to be stored without air, in a steady temperature in a cool and dark environment for it to last a year. It really should be used within 6 months instead. You can still use the products but be sure to mix them because the settle over time and can cause cracking. 4. Your treats are "milkbone" hard and are trying to use the Grain Free Frosting on them... try one of the "icings" instead. 5. You are using "frosting" instead of "icing" 6. You are using too thick of icing 7. You are dehydrating the icing or putting it in the oven to dry (use a fan instead) 8. You are using food colors that are reacting to the icing 9. You are using candy melts or other companies products with it 10. You are adding fruit or other ingredients to it