>>37641650>I'm wondering if that's what happened to some of these mapsNah, that's just what happens when you dump a map with a tileset that doesn't match (usually because the tileset doesn't exist anymore or was modified since the map was made). A lot of the beta maps embedded in retail G/S are the same way, see
https://tcrf.net/Pokémon_Gold_and_Silver/Unused_Maps