Unknown

Unknown is a placeholder block exclusive to Bedrock Edition that generates in place where blocks have an invalid ID or invalid components in their behavior files.

Obtaining
The block can be obtained in vanilla Minecraft with the or  commands, then broken with any tool, even TNT, or by hand in Survival.

Loading a block with an incorrect ID will result in it being replaced by an Unknown block, although it retains its ID.

Some Marketplace worlds that are meant for older versions of the game can generate this block. These may include worlds that haven’t updated to work with the latest version.

Behavior
Unknown blocks break instantly and have lower friction.

History
不明 Info update 未知方块