Fix Palworld Corrupted Save and Not a Compressed Palworld Save

When this is the problem

• A tool or script rejects the .sav with a message about it not being a compressed Palworld save.
• The error names b'PlM' where it expected b'PlZ'. That is a format label, not damage.
• The same save still loads in the game, or loaded until you tried to move it.
• Real corruption looks different: the game itself reports corrupted data, the world resets to an earlier state, or the file is far smaller than the other saves beside it.

Repair steps

1. Read the three bytes at offset 8 of the .sav, or just run the corrupted save checker. PlZ is the pre-0.6 zlib format. PlM is the Oodle format Palworld has written since 0.6, including 1.0. CNK means an Xbox or Game Pass wrapper around one of the other two.
2. If it says PlM, nothing is wrong with the save. Use a tool that reads the Oodle format; our converter decodes PlM in the browser and writes back PlZ, which the game still loads and rewrites on its next save.
3. If it says PlZ and still fails, the payload itself is the problem. A save with valid data followed by stray bytes is recoverable, and the checker will say so; a save that stops short of the length its own header declares is truncated and cannot be rebuilt.
4. For a truncated or unreadable save, restore from a backup instead. Palworld keeps rolling backups under the save folder, and your host panel or Game Pass sync may hold an older copy.
5. Only after you know which case you have should you change any file. Copy the save somewhere else first, and work on the copy.

Prevent it next time

• Keep a copy of the save folder before moving a world between single player, co-op and a dedicated server.
• Check what a save tool was last updated for. Anything written before Palworld 0.6 cannot read a modern save at all.
• Stop the server before copying a save. Files pulled while the game is writing are the usual source of genuine truncation.
• Keep the whole save folder together, not just the file you think matters.