While holding down right click, you can break a painting, pick it up, and instantly place it back down. This sometimes causes a "Ghost Item" to be picked up in your inventory. This item cannot be moved around or placed in chests, and right clicking at all or dropping the item will cause it to vanish, and so will relogging. If you pick an item and your inventory is full, the ghost painting will be replaced. Overall this item acts like it is not there (Because it isn't lol)
Steps To Reproduce:
Break a painting and then hold down right click.
Place the painting down instantly
Repeat until place painting but still receive item
This was tested on a LAN and Singleplayer world.
These recordings are compressed, but the game is running smooth for me.
This is fixed in the latest release. I tried it today and it doesn't seem to happen anymore.