When you middle click any bit collection it gives you an empty bit collection since the block NBT data is not copied. Once the item is in your inventory it will crash your game and effectively ban you from ever joining the world or server again. It will also crash other players looking at you in multiplayer servers but they can rejoin and still play as long as the "banned" player doesn't try rejoining while they are looking at them.
crash-2021-04-20_17.49.33-client.txt

BitandChisels - 2.1.3+21w10a
Minecraft - 21w10a & 21w15a

should be fully fixed in 2.4.0