Failed to initialize server: players folder

Your Minecraft server starts to boot, then stops before the Done line. Scroll up the Console and you'll find this warning, followed by the startup failure:

DETECTED OLD PLAYER DIRECTORY IN THE WORLD SAVE
Failed to initialize server

Your world folder holds a players folder left over from a very old Minecraft format, and the server won't start while it's there. Moving it out takes a few clicks in the File Manager.

Where the leftover folder comes from

Current Minecraft servers keep each player's data in world/playerdata. Very old versions used a folder called players instead. When the server finds one, it tries to convert it and refuses to start if the conversion fails.

The old folder usually arrives in one of two ways:

• You brought in an old save. The World Import tab installs the whole save folder as world, so everything inside it comes along, players included. The same goes for a world you upload yourself or copy across with the Migrate tab.
• Only part of an old world was deleted. Deleting level.dat or a handful of files leaves the rest of the old world in place, players included, and the next start stops before it loads a world.

If you changed World folder in the Config Editor, use that folder wherever these steps say world.

Move the players folder out of your world

1. If the server is still running, open the Console tab and press Stop in the bar under the console.

2. Open the File Manager and open the world folder. How to manage your server files covers the basics if the File Manager is new to you.

3. Click the players folder once to show its details. Leave playerdata alone, because it holds your players' current data.

4. Choose Move to…. The folder is part of your world, so the panel asks you to confirm.

5. Replace the Destination folder with / (the server root), type players to confirm, then press Move.

6. Go back to the Console tab and press Start. When the console shows Done (…s)!, the server has finished booting.

   

The old folder now sits in the server root, outside your world. Delete it from there once your players have checked their progress.

Delete it instead

If you're sure you don't need the old files:

1. With the server stopped, open world in the File Manager and click players.
2. Choose Delete. The panel asks Delete world data? because the folder sits inside your world.
3. Type players, press Delete, then go to the Console tab and press Start.

If the server still won't start

Match what happened just before the error:

• It started after a world import - stop the server, then in the File Manager delete the imported world folder and rename world.pre-import-… (its name ends in a timestamp) back to world. To keep the imported world instead, move its players folder out as described above.
• It started after a partial reset - finish the reset with the steps below.
• The Console now shows a different error - search the Help Centre for that line. A damaged level.dat, for example, has its own guide: No key dimensions in MapLike: fix level.dat.

Start again with a fresh world

1. Take a backup. Open the Backups tab and press Create backup. If every slot is used and Overwrite oldest when full is on, the new backup replaces your oldest unprotected one, so Download that one first if you want it. With the switch off, Create backup stays greyed out until you delete a backup. How to create and restore backups covers restoring.
2. If the server is running, open the Console tab and press Stop.
3. In the File Manager, delete world. Delete world_nether and world_the_end as well if your server has them (Paper and Purpur keep the Nether and the End in their own folders). The panel asks you to type each folder's name, or the word delete if you tick them together.
4. Go to the Console tab and press Start. The server generates a new world, and the console ends with Done (…s)!.

Stop it happening again

• Reset a world by deleting the whole set of world folders rather than single files inside them.
• Take a backup before you import or copy in a world, so you can restore the old one if the new save won't load.

If none of these fixed it

Gather these details:

• The Console output from the start of the boot down to Failed to initialize server.
• Where the world came from (World Import, your own upload or another host) and the Minecraft version it was last played on.
• The server software and version shown in the JAR Manager tab.
• Which of the steps above you tried.