Updated 23 October 2026. Facts on this page come from minecraft.wiki, minecraft.net and the live Artemis PvP server; sources are listed at the bottom.
Minecraft Server Connection Errors and Fixes
Most errors when joining a Minecraft server have a simple cause: "Outdated client" or "Outdated server" means your version does not match the server's, "Cannot resolve hostname" means the address is wrong, "Cannot connect to server" means the server is down or unreachable, and "Invalid session" is fixed by restarting the game.
What does "Outdated client" or "Outdated server" mean?
Your game version is different from the server's. You can only connect to servers with the same protocol version as your client, so pick the server's version in a launcher profile, or wait for the server to update. See every Minecraft version.
What do the other connection errors mean?
| Error | What it means | What to do |
|---|---|---|
| Cannot resolve hostname | No server exists at that address | Check the address for typos |
| Cannot connect to server | The server could not be reached | It may be down, your internet may be off, or it did not answer in time; try again later |
| Invalid session (Try restarting your game) | Your login session is out of date | Restart the game; only your newest session can join online-mode servers |
| End of stream | You connected too quickly | Disconnect, wait a moment and reconnect |
| The authentication servers are currently down for maintenance | Mojang's login servers are down | Check Service Statuses on help.minecraft.net |
| You are not whitelisted on this server! | The server only lets listed players in | Ask the server staff, often on its website or Discord |
| You are banned from this server! | Your account or IP is banned | Contact a server administrator |
How does a server whitelist work?
A whitelist (called an allowlist on Bedrock) checks each joining player's UUID (Java) or XUID (Bedrock) against a list, and turns away anyone not on it. Operators manage it with /whitelist or /allowlist. On Java, operators can always join even if they are not on the list; on Bedrock everyone must be listed. See how to make a server.
Can you join servers with a cracked launcher?
Not online-mode servers. A server checks your session with Mojang, so a cracked launcher can only join a server that has set online-mode=false in its properties. See how to join a server.
Why do you lag when you join a server?
On a slow device you may get a big lag spike as you enter. Lag also grows with lots of moving mobs and when players are spread far apart, because the server keeps chunks loaded around each of them. See how to improve FPS and chunks and ticks.
Which versions can join ArtemisPvP?
Frequently asked questions
What does Outdated client mean in Minecraft?
Your game version is different from the server's; switch to the server's version in the launcher.
Why does it say Cannot connect to server?
The server is down, your internet is off, or the server did not answer in time.
Sources
Every fact on this page was checked against these pages; the wording is ours.