How to recover missing Minecraft player data

If your Minecraft world loads correctly but players join with empty inventories, default spawn locations, or lost experience and Ender Chest contents, the player data is probably not corrupt. This commonly happens when the server's online-mode setting differs from the setting used by the previous server environment.

Why changing online mode affects player data

Minecraft Java Edition stores each player's data under their UUID (universally unique identifier). The same username receives a different UUID in online mode than it does in offline mode. After the mode changes, the server looks for a different player data file and creates a new one if it cannot find one. The original data normally remains in the world.

Restore the previous online-mode setting

1. Stop the server.
2. Open server.properties.
3. Find the online-mode setting.

4. Set it to the same value used by the previous server environment:

   online-mode=true
   

   Or, if the previous environment used offline mode:

   online-mode=false
   

5. Save the file and start the server.
6. Ask the affected player to reconnect and check their inventory, location, experience, and Ender Chest.

You may have disabled online mode previously so that friends without authenticated Minecraft accounts could join. If you do not specifically need offline mode, we recommend enabling online mode. It protects the server against username impersonation and unauthorized access.

If you want to change modes permanently

Changing the setting does not automatically convert existing player data to the new UUIDs. First restore the previous setting and confirm that the data is present. Then make a complete backup before migrating player data to the UUIDs used by the new mode. Player-specific files can exist in the world's playerdata, advancements, and stats folders.

Do not delete or overwrite these files while troubleshooting. If the data is still missing after restoring the previous setting, confirm that the correct world is selected and restore the affected player files from a backup.