Repair: `Io.Netty.Channel.ConnectTimeoutException` Error on Minecraft

Minecraft sometimes has unexpected problems that can completely ruin the fun, and the “io.netty.channel.ConnectTimeoutException connection timed” error is one of them.

Most users encounter the “io.netty.channel.ConnectTimeoutException connection timed out” error when trying to connect to a cooperative game on a local network or the Internet. In other cases, the problem is not related to a single server, but occurs constantly when trying to connect to any server.

What causes the error `Io.Netty.Channel.ConnectTimeoutException` in Minecraft Realms

JRE is blocked by third-party AV: This problem can also occur when using third-party AV such as Avast, Comodo, or McAfee. In this case, you can either disable your AV’s real-time protection or remove it completely to eliminate any possible interference with Minecraft.

JRE blocked by Windows Defender: If you use Windows Defender’s built-in anti-malware protection, you may see this error after the Java Runtime Environment is blocked from communicating with the Minecraft server due to a false positive. In this case, you can either whitelist the JRE or disable real-time protection to resolve the problem.

Default DNS mismatch: If you are using a second-tier ISP, you may also encounter this error due to a DNS mismatch. If this is the case, you can solve the problem by switching to the DNS values provided by Google.

Mismatched port numbers: This problem probably occurs when your client’s port number does not match the server’s port number. In this case, you can solve the problem by finding the correct port in the startup script and then using the direct connect option to successfully connect.

IP/TCP mismatch: One of the most common causes that can lead to this problem is an IP or CP mismatch enabled by your router. In this case, you can solve the problem simply by rebooting the router or, in more serious cases, by resetting it.

How to fix the “Io.Netty.Channel.ConnectTimeoutException” error in Minecraft Realms

Switch to Google DNS

  1. While holding down the Windows+R keys, open Run.
  2. Type Ncpa.CPL and click OK to open the Network Connections menu.
  3. In the Network Connections window, right-click the network device and select Properties.
  4. On the Network tab, under “This connection uses the following item” select “Internet Protocol version 4 (TCP / IPv4)” and click Properties.
  5. On the General tab, check Use the following DNS server address and replace the Preferred DNS server and Alternate DNS server with the following addresses:
    8.8.8.8
    8.8.4.4
  6. Click the OK button.
  7. Then select Internet Protocol version 6 (TCP / IPv6) and click Properties.
  8. On the General tab, select the Use the following DNS server address check box and replace the Preferred DNS server and Alternate DNS server with the following addresses:
    2001:4860:4860::8888
    2001:4860:4860::8844
  9. Click OK.
  10. Close the Internet Properties window.
  11. Then restart your computer and start Minecraft.

Turn off the Windows Defender firewall

  1. Press and hold Windows+R to open the Run dialog box.
  2. In the Run dialog box, type control firewall.CPL and click OK to open the Windows Defender firewall settings.
  3. Click Enable or disable the Windows Defender firewall.
  4. Select the Disable Windows Defender firewall (not recommended) for private and public networks check box.
  5. To re-enable Windows Defender Firewall later, select the Enable Windows Defender Firewall for private and public networks check box.
  6. Click OK to confirm.
  7. Start Minecraft.

Frequently Asked Questions

  1. Add exceptions to the firewall settings in your Minecraft folder.
  2. Remove unstable software.
  3. Add an IP address and select an appropriate working port.
  4. Reboot the modem/router.
  5. Use a reliable VPN connection source.
  6. Update your Java software.
  7. Reinstall Minecraft.

Io.Netty.Channel.ConnectTimeoutException means that your connection to the remote server has timed out. The server connection timeout means that it takes too long for the server to respond to a data request from another device.

  1. Adjust your firewall settings.
  2. Disable VPN and antivirus software.
  3. Reset your router settings.
  4. Check your IPv4 address.

  1. Check the Minecraft server.
  2. Reset your network settings.
  3. Allow Minecraft in your firewall.
  4. Temporarily disable antivirus software.
  5. Use port forwarding.
  6. Change the version of your Minecraft.
  7. Use VPN services.