So for my mod I want to remove the item form the players inventory with onItemRightClick() but whenever I try this the game crashes. I have looked all over the internet and in the minecraftForge classes to find out how to do this but everything I try dosent work, here is the code for the method:

 

    @Override

    public ItemStack onItemRightClick(ItemStack stack, World world, EntityPlayer player)

    {

        if(stack.getItemDamage()==2 && this.getResearch()!=null && player.getEntityData().getTag(this.getResearch())==null)

        {

            PlayerResearch.addResearch(player, this.getResearch());

            stack.stackSize--;

        }

        return stack;

    }

 

Any help would be appreciated

Crash report please. I'm sure it crashes not on stack.stacksize--;

Do the nullChecks before checking the item dmg.

Managed to solve the problem, it was actually being caused by the NBTTagCompound not being declared properly, DERP!