Can't connect to your Minecraft server? Check these in order

1. Is the server running?

Open the Console tab. If the server is stopped, start it. If it is starting, wait for the line with Done; a player who tries earlier gets Connection refused. Big modpacks can take several minutes to get there.

Did it stop by itself? The last lines of the console usually show why. If they mention a Java or class version, see which Java version your server needs.

2. Is the address right?

• Copy the address from the Overview tab instead of typing it. A missing letter gives Can't resolve hostname or Unknown host.
• Java players type only the address. Bedrock players also fill in the port the panel shows, in the separate port field.
• No spaces before or after the address. Some phones add one when pasting.

Just added a new address in Settings? It can take a few minutes before every network knows it. Players on some networks may need to restart the game or their router once.

3. Do the versions match?

The player can pick the server's version in the Minecraft Launcher under Installations. Or you let several versions in with the ViaVersion plugin, which lets newer clients join an older Paper server.

Bedrock updates on its own, so a Bedrock player is always on the newest version. On a crossplay server, keep Geyser up to date to follow.

4. Is the player allowed in?

• You are not whitelisted on this server: add their exact username in the Players tab. For Bedrock players on crossplay, use fwhitelist add with their name.
• You are banned from this server: check the ban list in the Players tab and pardon them if it was a mistake.
• The server is full: raise max-players in server.properties, or wait for a slot.

5. Failed to verify username

The server checks with Mojang that the player really owns the account. This fails when:

• The player uses an unofficial launcher without a real Microsoft account. They need to buy and sign in to Minecraft.
• The player's session expired. Restarting the Minecraft Launcher and signing in again fixes it.
• Mojang's login servers have a hiccup. Wait a few minutes; it affects many servers at once when it happens.

Do not turn off online-mode to get around it. That setting is what stops a stranger from logging in as you or as one of your operators.

6. Timed out

Connection timed out means no answer came in time. If only one player has it, the cause is on their side: a school or work network that blocks games, a VPN, or a firewall on their computer. Ask them to try on a phone hotspot to be sure.

If everyone has it, the server itself is overloaded or stuck. Check the console for lag warnings and see reduce lag on your server.

7. Modded servers

Messages about missing mods, a mismatched mod list or registry errors mean the player's mods differ from the server's. The fix is always the same: exactly the same pack at exactly the same version. Send them join a modded server.

8. Bedrock cannot connect but Java can

On a crossplay server this is nearly always the Geyser port. It must match the Bedrock port the panel shows; if someone set it to 19132, Bedrock players get Unable to connect to world. Java and Bedrock crossplay explains the setting.