When Minecraft refuses to join a server, the message on the screen usually tells you what went wrong, even if it is short and a little cryptic. This guide goes through the errors players see most often, what each one means, and what you can do about it. Most of them are fixed in a minute once you know whether the problem is on your side, the server's side, or somewhere in between.
"Outdated client" or "Outdated server"
This is a version mismatch. Depending on the server software, the message reads Outdated client! Please use 26.1, Outdated server! I'm still on 1.21.4 or Incompatible client! Please use 26.2. In the multiplayer list the server's version is shown in red before you even try to join.
- Outdated client means your game is older than the server. Update the game, or create a launcher installation with the exact version the server asks for.
- Outdated server means your game is newer than the server. Create an installation with the older version the message names.
Many servers accept a range of versions through a protocol plugin, but not all of them, and support for brand-new releases often arrives a few days late. Since 2026 Minecraft uses year-based version numbers (26.1, 26.2 and so on) instead of the old 1.x scheme, so a server that says it supports "1.20 to 26.2" covers everything between 1.20 and the newest release. Every server page on our server list shows the versions it reports, so you can check before you start the game.
"Failed to verify username" and "Invalid session"
The full messages are Failed to verify username! and Failed to login: Invalid session (Try restarting your game and the launcher). On premium servers (also called online mode) the server asks Microsoft's authentication service to confirm that you own the account. These errors mean that check failed.
- Close the game completely, then restart the launcher.
- If that does not help, sign out of the launcher and sign back in with your Microsoft account.
- Check that you are not running two copies of the game with the same account.
- Wait a few minutes and try again. Authentication services occasionally have outages, and then nobody can join premium servers.
If you play without a purchased account, you can only join non-premium (offline mode) servers; premium servers will always reject you. The reverse also happens: some non-premium servers use a login plugin and ask you to register a password with /register and log in with /login on every visit. Our list marks servers with premium and non-premium badges so you know which kind you are joining.
"Connection timed out" and "Can't connect to server"
You will usually see Connection timed out: no further information, Connection refused: no further information or just Can't connect to server. Your game reached out and either got no answer or was turned away. Possible causes, from most to least likely:
- Wrong address or port. Copy the address again and check for typos. If the server uses a port other than the default 25565, it must be added after a colon, as in
play.example.com:25570. - The server is offline or restarting. Check its live status on its page in our list. If it shows offline there too, the problem is not on your side.
- Firewall or antivirus. Make sure Java, or the launcher's bundled Java runtime, is allowed through your firewall on both private and public networks.
- Restricted network. School, office, hotel and some public Wi-Fi networks block game traffic. Try a different network or your phone's hotspot to confirm.
- Unstable Wi-Fi. Move closer to the router or use a cable. Timeouts that happen in the middle of play, not while connecting, usually point to your connection.
- VPN. Some servers block VPN addresses. Turn the VPN off and try again.
"Connection refused" specifically means something answered at that address but nothing is listening on that port. That points to a wrong port or a server that has just crashed.
"Unknown host"
Older versions show Unknown host, newer ones Can't resolve hostname. The game could not turn the address you typed into an IP address. Check the spelling first. If the address is correct, the domain may have expired or been changed, so look up the current address on the server's page. Rarely, your DNS is at fault: restarting the router, or switching your device to a different DNS resolver, usually solves it.
"You are banned from this server"
The message is You are banned from this server., often followed by a reason and an expiry date. Your IP address is banned from this server. means the ban applies to your network, not only your account, which can happen if someone else on the same network was banned. Nothing on your computer will fix a ban. Use the appeal channel the server names in the message, usually a Discord server or a web form. Do not try to get around it with another account or a VPN; ban evasion almost always makes the ban permanent.
"The server is full"
The server is full! means every slot is taken. Try again in a few minutes; slots free up constantly on busy servers. Some servers keep reserved slots or a queue for ranked players. Player counts on our list are updated live, so you can see how close a server is to its limit.
Whitelist
You are not whitelisted on this server! (older versions say white-listed) means only approved players can join. Many private SMPs work this way. Look for an application form, usually on the server's Discord, and send the exact username you play with, since the whitelist checks it letter by letter.
Mod and modpack mismatch on modded servers
Modded servers need your client to load the same mod loader, the same mods and usually the same mod versions. Typical messages mention Mod rejections, Incompatible mod set or missing mods by name, and some simply disconnect you during loading. To fix it:
- Install the exact modpack and pack version the server names, ideally through the launcher the server recommends.
- Check that the game version and mod loader version match.
- Remove extra client mods you added yourself, then add them back one by one if the server allows them.
- Give the game enough memory; large packs often need 6 to 8 GB.
The modded servers page lists servers of this kind together with the versions they run.
Bedrock Edition and port 19132
Bedrock players on phones, consoles and Windows connect differently. Bedrock uses port 19132 by default, and it uses UDP rather than TCP. If you see Unable to connect to world, check that you entered the Bedrock address and port, not the Java ones; they are often different on servers that support both editions. On consoles, adding external servers may require a workaround or may only be possible for featured servers, so check the server's instructions. Servers that accept both Java and Bedrock players carry a badge on our list showing that.
Quick checklist
- Is the address correct, with the right port after a colon if needed?
- Does your game version match one the server supports?
- Is the server online right now according to its live status?
- Have you restarted the game and the launcher, and signed in again?
- Is it a premium server, and do you own the game?
- Is Java allowed through your firewall, and is your VPN off?
- Does another network, such as a phone hotspot, work?
- For modded servers: exact modpack, mod loader and enough memory?
- For Bedrock: the Bedrock address and port 19132, not the Java ones?
If none of this helps, contact the server's staff with the exact error message; it saves both of you time. If you run a server yourself, our page for server owners explains how listing works.