An older Minecraft cannot read a world saved by a newer one. When you keep your files in Edit Server Type and pick an older version than your world was last saved by, the panel stops before changing anything and says Nothing was changed: your world is at risk. (With Delete my existing files and start clean (recommended). ticked, nothing is checked: the files, world included, are deleted and the older version starts with a new world.) To keep the world, choose its version or a newer one. To go back to an older version for real, restore a backup taken before the upgrade.
What the panel says
The panel reads the version your world was last saved by and compares it with the one you picked. Its message says, for example, that This world was last saved by Minecraft one version and the one you picked is older, and that the server would refuse to start, and forcing it can damage the world.
Your three choices
- Choose another version: back to the version step. Pick the version your world was saved by, or a newer one. This keeps your world and is the safe choice.
- Start clean instead: deletes the files on the server and installs the older version on an empty server, with a new world. A safety backup of the world is saved first when your plan has room for one.
- Keep my files and install anyway: installs the older version over your files as they are. The panel warns that this may leave a server that will not start. Take a backup first.
Go back after an upgrade
A world that a newer Minecraft has opened has been converted, and the old version cannot read it. The way back is a backup made before the upgrade, together with the old version: see How to back up, restore and reset your Minecraft world. If you are not sure how to combine the two, open a ticket before you change anything and we will help.
Back up first (recommended) and Try it on a copy first in the Change server type window exist for this reason: next time, use one of them before moving to a newer version. See How to change your Minecraft version or server type.
Good to know
- A newer Minecraft converts your world to its own version the first time it loads it, with no way back except a backup.
- If only your friends' games are newer than the server, you do not need to downgrade anything: Players see Outdated client or Outdated server on your Minecraft server.
