GUI Error 1.14.4 2020.1

Status
Resolved
Issue description

I wanna make an UI with 1 in and output slot, but when i click save i get this error:

 

		@Override
		/* failed to load code for net.minecraft.inventory.container.Container */
		@Override
		public void onContainerClosed(PlayerEntity playerIn) {
			super.onContainerClosed(playerIn);
		}

Picture of GUI given below, Block too, please Help!

Issue comments