Don't copy half-blocks

[Diedman9T]

When I copy the territory and paste it, half-blocks and grass were replaced on unknown-dirt block.

[Diedman9T]

Here's what I noticed: as long as the object is in the buffer, everything is fine. as soon as you save it in .schem, the grass and half-blocks (cobblestones) break

[platz1de]

This is caused by the required data files not being updated yet (Mojang changed the block names for slabs in 1.21)