Introduction: The bug is when you get a item and do the fast swap, the item lose the existence. You cant place it, you cant craft it, only if you press E again. (Only works on hotbar o think)

1. Get a random item.

2. Press E and put your mouse on it.

3. Press a number of other hotbar slot.

4. Close the inventory.

5. Now try to place this block, try to drop this block. You cant.

6. Now press E again.

7. Close the inventory.

8. Now you can place it, drop it and do the normal stuff.