I have an item that when right clicked spawns a mob with my custom AI in a radius around the player. It's working perfectly except that it spawns the mob with its default AI. I've been testing on Zombies only, I debugged the code and it does step into the condition and execute all the removeTask code. I'm not really sure what do from here so any help would be appreciated.

@Override
public ActionResult<ItemStack> onItemRightClick(ItemStack itemStackIn, World worldIn, EntityPlayer playerIn, EnumHand hand)
    {
	if(itemStackIn.getTagCompound().getInteger("MobCounter") > 0 && !worldIn.isRemote)
	{
		int mobCounter = itemStackIn.getTagCompound().getInteger("MobCounter");
		final int spawnRange = 4;
		--mobCounter;
		EntityMob entity = (EntityMob) EntityList.createEntityByName(itemStackIn.getTagCompound().getString("Mob"+Integer.toString(mobCounter)), worldIn);
		entity.setPosition((double)playerIn.getPosition().getX() + (worldIn.rand.nextDouble() - worldIn.rand.nextDouble()) * (double)spawnRange + 0.5D, (double)(playerIn.getPosition().getY() + worldIn.rand.nextInt(2)), (double)playerIn.getPosition().getZ() + (worldIn.rand.nextDouble() - worldIn.rand.nextDouble()) * (double)spawnRange + 0.5D);
		if(entity instanceof EntityZombie)
		{
			entity.tasks.removeTask(new EntityAIMoveThroughVillage(entity, 1.0D, false));
			entity.tasks.removeTask(new EntityAIHurtByTarget(entity, true, new Class[] {EntityPigZombie.class}));
			entity.tasks.removeTask(new EntityAINearestAttackableTarget(entity, EntityPlayer.class, true));
			entity.tasks.removeTask(new EntityAINearestAttackableTarget(entity, EntityVillager.class, false));
			entity.tasks.removeTask(new EntityAINearestAttackableTarget(entity, EntityIronGolem.class, true));
			entity.tasks.addTask(5, new EntityMobAiFollow(entity, playerIn, 1.0D,10.0F,2.0F)); //Custom AI Class
		}
		worldIn.spawnEntityInWorld(entity);
        itemStackIn.getTagCompound().setInteger("MobCounter", mobCounter);
	}
        return new ActionResult(EnumActionResult.PASS, itemStackIn);
    }

I have an item that when right clicked spawns a mob with my custom AI in a radius around the player. It's working perfectly except that it spawns the mob with its default AI. I've been testing on Zombies only, I debugged the code and it does step into the condition and execute all the removeTask code. I'm not really sure what do from here so any help would be appreciated.

@Override
public ActionResult<ItemStack> onItemRightClick(ItemStack itemStackIn, World worldIn, EntityPlayer playerIn, EnumHand hand)
    {
	if(itemStackIn.getTagCompound().getInteger("MobCounter") > 0 && !worldIn.isRemote)
	{
		int mobCounter = itemStackIn.getTagCompound().getInteger("MobCounter");
		final int spawnRange = 4;
		--mobCounter;
		EntityMob entity = (EntityMob) EntityList.createEntityByName(itemStackIn.getTagCompound().getString("Mob"+Integer.toString(mobCounter)), worldIn);
		entity.setPosition((double)playerIn.getPosition().getX() + (worldIn.rand.nextDouble() - worldIn.rand.nextDouble()) * (double)spawnRange + 0.5D, (double)(playerIn.getPosition().getY() + worldIn.rand.nextInt(2)), (double)playerIn.getPosition().getZ() + (worldIn.rand.nextDouble() - worldIn.rand.nextDouble()) * (double)spawnRange + 0.5D);
		if(entity instanceof EntityZombie)
		{
			entity.tasks.removeTask(new EntityAIMoveThroughVillage(entity, 1.0D, false));
			entity.tasks.removeTask(new EntityAIHurtByTarget(entity, true, new Class[] {EntityPigZombie.class}));
			entity.tasks.removeTask(new EntityAINearestAttackableTarget(entity, EntityPlayer.class, true));
			entity.tasks.removeTask(new EntityAINearestAttackableTarget(entity, EntityVillager.class, false));
			entity.tasks.removeTask(new EntityAINearestAttackableTarget(entity, EntityIronGolem.class, true));
			entity.tasks.addTask(5, new EntityMobAiFollow(entity, playerIn, 1.0D,10.0F,2.0F)); //Custom AI Class
		}
		worldIn.spawnEntityInWorld(entity);
        itemStackIn.getTagCompound().setInteger("MobCounter", mobCounter);
	}
        return new ActionResult(EnumActionResult.PASS, itemStackIn);
    }

removeTask(new Task())

isn't going to do anything.  It won't find the newly created object in the array, so it won't remove it from the array.

removeTask(new Task())

isn't going to do anything.  It won't find the newly created object in the array, so it won't remove it from the array.

I kind of assumed this so I edited the code like this but it's still not working.

public ActionResult<ItemStack> onItemRightClick(ItemStack itemStackIn, World worldIn, EntityPlayer playerIn, EnumHand hand)
    {
	if(itemStackIn.getTagCompound().getInteger("MobCounter") > 0 && !worldIn.isRemote)
	{
		int mobCounter = itemStackIn.getTagCompound().getInteger("MobCounter");
		final int spawnRange = 4;
		--mobCounter;
		EntityMob entity = (EntityMob) EntityList.createEntityByName(itemStackIn.getTagCompound().getString("Mob"+Integer.toString(mobCounter)), worldIn);
		entity.setPosition((double)playerIn.getPosition().getX() + (worldIn.rand.nextDouble() - worldIn.rand.nextDouble()) * (double)spawnRange + 0.5D, (double)(playerIn.getPosition().getY() + worldIn.rand.nextInt(2)), (double)playerIn.getPosition().getZ() + (worldIn.rand.nextDouble() - worldIn.rand.nextDouble()) * (double)spawnRange + 0.5D);
		if(entity instanceof EntityZombie)
		{
			for(Object task : entity.tasks.taskEntries.toArray())
			{
				 EntityAIBase ai = ((EntityAITaskEntry) task).action;
				 if(ai instanceof EntityAIMoveThroughVillage || ai instanceof EntityAIHurtByTarget || ai instanceof EntityAINearestAttackableTarget)
					 entity.tasks.removeTask(ai);		 
			}
			entity.tasks.addTask(5, new EntityMobAiFollow(entity, playerIn, 1.0D,10.0F,2.0F));
		}
		worldIn.spawnEntityInWorld(entity);
        itemStackIn.getTagCompound().setInteger("MobCounter", mobCounter);
	}

I kind of assumed this so I edited the code like this but it's still not working.

public ActionResult<ItemStack> onItemRightClick(ItemStack itemStackIn, World worldIn, EntityPlayer playerIn, EnumHand hand)
    {
	if(itemStackIn.getTagCompound().getInteger("MobCounter") > 0 && !worldIn.isRemote)
	{
		int mobCounter = itemStackIn.getTagCompound().getInteger("MobCounter");
		final int spawnRange = 4;
		--mobCounter;
		EntityMob entity = (EntityMob) EntityList.createEntityByName(itemStackIn.getTagCompound().getString("Mob"+Integer.toString(mobCounter)), worldIn);
		entity.setPosition((double)playerIn.getPosition().getX() + (worldIn.rand.nextDouble() - worldIn.rand.nextDouble()) * (double)spawnRange + 0.5D, (double)(playerIn.getPosition().getY() + worldIn.rand.nextInt(2)), (double)playerIn.getPosition().getZ() + (worldIn.rand.nextDouble() - worldIn.rand.nextDouble()) * (double)spawnRange + 0.5D);
		if(entity instanceof EntityZombie)
		{
			for(Object task : entity.tasks.taskEntries.toArray())
			{
				 EntityAIBase ai = ((EntityAITaskEntry) task).action;
				 if(ai instanceof EntityAIMoveThroughVillage || ai instanceof EntityAIHurtByTarget || ai instanceof EntityAINearestAttackableTarget)
					 entity.tasks.removeTask(ai);		 
			}
			entity.tasks.addTask(5, new EntityMobAiFollow(entity, playerIn, 1.0D,10.0F,2.0F));
		}
		worldIn.spawnEntityInWorld(entity);
        itemStackIn.getTagCompound().setInteger("MobCounter", mobCounter);
	}

Be careful when looping and removing at the same time. Some of these objects will put you in the wrong place so that you miss something. Check the forum for discussions of when to use an iterator etc.

Be careful when looping and removing at the same time. Some of these objects will put you in the wrong place so that you miss something. Check the forum for discussions of when to use an iterator etc.

After some debugging I figured it out. I somehow missed that some of the AI tasks are added in the targetTasks instead of tasks. Adding another loop for targetTasks fixed the issue. I apologize for the inconvenience