[1.12.2]Problem with tile entity

[tt36999]

My tileentity have two fluid tank and i want fill one of tanks when right click this block with fluid bucket.

But when i test my tileentity, the sever side(when world.isRemote == flase)tank always null when block actived, client side working properly

@Override
    public boolean onBlockActivated(World worldIn, BlockPos pos, IBlockState state, EntityPlayer playerIn, EnumHand hand, EnumFacing facing, float hitX, float hitY, float hitZ) {
        ItemStack itemHeld = playerIn.getHeldItem(hand);
        IFluidHandlerItem handlerItem = FluidUtil.getFluidHandler(itemHeld);
        if (handlerItem != null) {
            TileEntityPurifier purifier = (TileEntityPurifier) worldIn.getTileEntity(pos);// BreakPoint 1 in this line server side tileentity's tank always empty
            IItemHandler iItemHandler = new InvWrapper(playerIn.inventory);
            FluidActionResult emptyResult = FluidUtil.tryEmptyContainerAndStow(itemHeld, purifier.tank, iItemHandler, purifier.tank.getCapacity(), playerIn, true);//I break this line , idea show me fluid has filled into tileentity, both side fluid amoount changed
            if (emptyResult.isSuccess()) {
                playerIn.setHeldItem(hand, emptyResult.getResult());
                worldIn.markChunkDirty(pos, purifier);
                return true;
            }
            FluidActionResult fillResultOut = FluidUtil.tryFillContainerAndStow(itemHeld, purifier.outputTank, iItemHandler, purifier.outputTank.getFluidAmount(), playerIn, true);
            if (fillResultOut.isSuccess()) {
                playerIn.setHeldItem(hand, fillResultOut.getResult());
                worldIn.markChunkDirty(pos, purifier);
                return true;
            }
            FluidActionResult fillResult = FluidUtil.tryFillContainerAndStow(itemHeld, purifier.outputTank, iItemHandler, purifier.tank.getFluidAmount(), playerIn, true);
            if (fillResult.isSuccess()) {
                playerIn.setHeldItem(hand, fillResult.getResult());
                worldIn.markChunkDirty(pos, purifier);
                return true;
            }
        } else {
            BrewingCraft.openGui(playerIn, getGui(), worldIn, pos.getX(), pos.getY(), pos.getZ());
            return true;
        }
        return false;
    }

any idea to fix this?