After installing this mod and loading up my world it was spamming console about gamerules being set to false and then after a few minutes I crashed and the crashlog said :

java.lang.NoSuchMethodError: net.minecraft.world.World.func_82732_R()Lnet/minecraft/util/Vec3Pool;
at projectzulu.common.mobs.entityai.RandomPositionGenerator.findRandomTargetBlock(RandomPositionGenerator.java:98)
at projectzulu.common.mobs.entityai.RandomPositionGenerator.findRandomTarget(RandomPositionGenerator.java:21)
at projectzulu.common.mobs.entityai.EntityAIWander.func_75250_a(EntityAIWander.java:43)
at net.minecraft.entity.ai.EntityAITasks.func_75774_a(SourceFile:70)
at net.minecraft.entity.EntityLiving.func_70619_bc(EntityLiving.java:540)
at projectzulu.common.mobs.entity.EntityAerial.func_70619_bc(EntityAerial.java:96)
at projectzulu.common.mobs.entity.EntityGenericCreature.func_70619_bc(EntityGenericCreature.java:93)
at projectzulu.common.mobs.entity.EntityGenericBreedable.func_70619_bc(EntityGenericBreedable.java:34)
at projectzulu.common.mobs.entity.EntityGenericTameable.func_70619_bc(EntityGenericTameable.java:197)
at projectzulu.common.mobs.entity.EntityGenericAnimal.func_70619_bc(EntityGenericAnimal.java:94)
at net.minecraft.entity.EntityLivingBase.func_70636_d(EntityLivingBase.java:1772)
at net.minecraft.entity.EntityLiving.func_70636_d(EntityLiving.java:367)
at projectzulu.common.mobs.entity.EntityGenericBreedable.func_70636_d(EntityGenericBreedable.java:39)
at projectzulu.common.mobs.entity.EntityGenericAnimal.func_70636_d(EntityGenericAnimal.java:127)
at net.minecraft.entity.EntityLivingBase.func_70071_h_(EntityLivingBase.java:1609)
at net.minecraft.entity.EntityLiving.func_70071_h_(EntityLiving.java:206)
at projectzulu.common.mobs.entity.EntityGenericCreature.func_70071_h_(EntityGenericCreature.java:101)
at projectzulu.common.mobs.entity.EntityGenericAgeable.func_70071_h_(EntityGenericAgeable.java:36)
at projectzulu.common.mobs.entity.EntityGenericTameable.func_70071_h_(EntityGenericTameable.java:202)
at net.minecraft.world.World.func_72866_a(World.java:2070)
at net.minecraft.world.WorldServer.func_72866_a(WorldServer.java:648)
at net.minecraft.world.World.func_72870_g(World.java:2034)
at net.minecraft.world.World.func_72939_s(World.java:1887)
at net.minecraft.world.WorldServer.func_72939_s(WorldServer.java:489)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:636)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:547)
at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:111)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:427)
at net.minecraft.server.MinecraftServer$2.run(MinecraftServer.java:685)