Read the slot map correctly
An MCA region starts with two 4 KiB header sectors. One stores 1,024 chunk locations and allocated sector counts; the other stores timestamps. Local coordinates run from zero to 31 in both axes, and the slot number is x + 32 × z. Slot 33 therefore represents local coordinates 1,1, not an absolute world position.
Region inspection checks allocation bounds, overlapping sectors, stored chunk lengths and supported compression identifiers. A header-ready label means that the envelope passed these checks. It does not mean that every compressed payload has been opened, or that the world is healthy. Unsupported and invalid entries remain visible in the map.
Decode one known occupied slot
Choose an occupied slot and run the inspection again. Supported gzip, zlib and uncompressed payloads are decoded into Java NBT and checked against the same bounds as standalone files. A successful result offers a raw NBT copy of that selected chunk. Empty, malformed or unsupported slots produce an explicit finding rather than an invented replacement.
The generated region example contains three occupied slots with the supported compression methods. Use it to understand the map and download behavior, then inspect your own region. It is a serialization example, not a complete playable Minecraft world or a guarantee that arbitrary chunk content satisfies the game’s rules.
Keep the evidence within its scope
External .mcc chunk payloads and newer LZ4 compression are not decoded in this release. Region files must have complete 4 KiB sectors and remain within 32 MiB. A truncated file or an oversized chunk needs another dedicated workflow; removing a header entry is not recovery of its former contents.
Chunk NBT may contain coordinates, version information, sections and other structures, but this tool does not validate every Minecraft data rule. Entity and point-of-interest files can live in separate folders, and neighboring chunks may refer to related state. Keep your original files and use game-level checks on a separate copy when evaluating a repair.