Sometimes a player gets stuck in a crash-loop, or you just want to let someone start their journey from scratch. Resetting a single player’s progress is much safer than wiping the whole world.

Step 1: Find the Player's UUID

Minecraft identifies players by a long string of numbers and letters called a UUID.

Go to a site like MinecraftUUID.com.
Enter the player's username.
Copy the Full UUID (e.g., 069a79f4-44e9-4726-a5be-fca90e38aaf5).

Step 2: Delete Their Progress Files

Stop your server in Mission Control.
Go to the Files tab.
Open your world folder (usually named world).
Look for the playerdata folder.
Find the file named [UUID].dat and Delete it.
Optional: Repeat this in the advancements and stats folders to completely clear their achievements and scores.

Step 3: Clear the Cache

To make sure the server doesn’t "remember" them, go back to the root folder (where your world folder is) and delete usercache.json.

Step 4: Restart

Start your server. The next time that player joins, they will spawn at the world spawn point with an empty inventory, just like a brand-new player.

Warning: This process deletes everything that player was carrying. If they had rare items, those are gone forever! Always take a Snapshot first.