Fix “Internal Exception: An existing connection was forcibly closed by the remote host” in Minecraft
This message means the connection was working and then was cut, so you did reach the server. Something dropped it: the server, a plugin, your network or a filter in between. The words after “Internal Exception” narrow it down.
Read the exception
| Message | What it usually means |
|---|---|
| An existing connection was forcibly closed by the remote host | The other side closed the connection: the server stopped or kicked you, or something on the network cut it. Mac and Linux show “Connection reset” for the same thing. |
| io.netty.handler.timeout.ReadTimeoutException | No data arrived from the server for about 30 seconds. The server froze or lagged badly, or your connection stalled. |
| io.netty.handler.codec.DecoderException | The game and the server disagree about the data. Look for a version mismatch, a broken mod, or a proxy or plugin sending bad packets. |
Checks for players
- Check that the server is still up. If everyone was kicked at once, the server crashed or restarted. Ask in the community's Discord.
- Match versions and mods. Use the server's Minecraft version, and for a modded server the same mods and versions.
- Turn off your VPN and try another network, such as a phone hotspot. Restart your router, and use a cable instead of Wi-Fi if you can.
- Allow Minecraft through your security software. Some antivirus programs and firewalls close game connections. Allow Java and the launcher.
Checks for server owners
1. Look at the log at that moment
Open logs/latest.log at the time of the disconnect. A crash, a watchdog message or repeated “Can't keep up!” warnings explain it. A server that freezes for 30 seconds makes every player time out; see how to fix server lag.
2. Look for plugins that kick players
Anti-cheat and rate-limit plugins can close connections. Look for kick lines around the time of the error, and disable the plugin for a test.
3. Match compression settings
On a proxy network, the proxy and the game servers must agree on network compression. The setting is network-compression-threshold in server.properties, and the proxy's own config has a matching option. Follow the proxy's documentation, and keep the same setting on every game server.
4. Check your firewall and DDoS filter
Connection limits and rate limits can reset new connections from many players at once, or from players who share an address. Look at your firewall rules and fail2ban jails, and see how to protect a Minecraft server from DDoS attacks for filtering that doesn't lock out real players.
5. Check the forwarding settings behind a proxy
Velocity and BungeeCord need matching forwarding settings on the proxy and on every game server. A mismatch closes the connection as soon as a player is sent to the server.
6. Only some players affected?
If players on one internet provider or in one country are cut while others stay connected, the route from their network is the problem. Ask for their IP address and the time it happened, and send both to your host.
Still happening?
Collect the time of the disconnect, the player's IP address, the exception text and the matching part of the server log. With those, the cause can usually be found quickly.
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