Crash when spawning mobs in 1.7.10. Any ideas on a fix?

Using Mcreator for 1.7.10. Made an item that shoots a Blaze fireball. It loads fine but when I try to fire it it crashes the game and states "java.lang.ClassCastException: net.minecraft.entity.projectile.EntitySmallFireball cannot be cast to net.minecraft.entity.EntityLiving".  

 I saw frigging somewhere that it was an error in the code Mcreator spits out and that there's a really simple fix for it, but I cannot find it anywhere. I could really use some help. I'm not finding any help or any support anywhere and I'm at the end of my rope on this.