Minecraft won't start or stops at once

A new Minecraft server is set up but still stopped. On its first start it shuts down again right away until you have accepted the EULA. That is not a fault but Mojang's rule.

What the EULA is

The EULA is Mojang's end user licence for Minecraft. Every Minecraft server starts only once its operator has accepted it. The operator is you, so only you can accept it; we do not do it for you.

Where you accept it

1. 1

   Open the overview

   Open the server under Servers. Its Overview shows the note Minecraft is waiting for your consent with a link to the EULA.

2. 2

   Accept

   Read the EULA and press Accept and start. The portal writes your consent into the file eula.txt and starts the server.

3. 3

   Watch it start

   The Console shows the server creating its world. The first start takes a little longer.

If the server has already shut down once, the console also shows the EULA note under Found in the log, with the same button.

Other reasons on the first start

If the server still does not start after you accepted, or it crashes, the console lists under Found in the log what it found in the log, with a button to the place where you fix it:

Wrong Java version

"This version needs Java 21 or newer": choose the Java version in the Startup tab. It applies from the next start.

Not enough memory

"The memory was not enough": often a large modpack or many mods. The Java settings are under Startup; more memory comes with another plan.

Mods or plugins do not fit

A mod lacks a dependency or was built for another version: the Plugins tab (Mods with Fabric, Forge and NeoForge) shows what is installed (more).

Port in use

A configuration names another port than the assigned one: Network shows the server's ports.

Disk full

The server cannot write any more: delete old worlds, logs or backups under Files and Backups.