How do I troubleshoot the "Port Forwarding Failed" error?

The ''Port Forwarding Failed'' error in Valheim is a common issue when trying to host or join a multiplayer server. This error occurs when the game cannot properly communicate with the internet due to network configuration issues. Port forwarding is essential for allowing external players to connect to your server, and failing to set it up correctly can prevent multiplayer gameplay.\n\nTo troubleshoot this error, start by ensuring your router supports port forwarding. Most modern routers do, but older models may not. Access your router''s settings by typing its IP address into your web browser. Common router IPs include 192.168.1.1 or 192.168.0.1. Log in using your router''s admin credentials, which are often found on the router itself or in its manual.\n\nOnce logged in, locate the port forwarding section in your router''s settings. This is typically found under ''Advanced Settings'' or ''Network Settings.'' You will need to forward port 2456 for both TCP and UDP protocols. This is the default port Valheim uses for multiplayer connections. Enter the IP address of the device hosting the server (your PC or dedicated server) and save the changes.\n\nAfter configuring port forwarding, restart your router to apply the changes. Next, ensure your firewall or antivirus software is not blocking Valheim. Add an exception for Valheim in your firewall settings to allow it to communicate over the internet. On Windows, this can be done by navigating to ''Windows Defender Firewall'' and adding Valheim.exe to the allowed apps list.\n\nIf the error persists, check if your internet service provider (ISP) is blocking the port. Some ISPs restrict certain ports for security reasons. Contact your ISP to confirm if port 2456 is accessible. If it is blocked, you may need to use a VPN or request your ISP to unblock the port.\n\nFor players using a dedicated server, ensure the server configuration file (start_headless_server.bat) is correctly set up. Open the file in a text editor and verify the port number is set to 2456. Additionally, ensure the server is running on a stable connection with sufficient bandwidth to handle multiple players.\n\nFinally, test your setup by having a friend attempt to join your server. If they can connect successfully, the issue is resolved. If not, double-check all settings and consider using a third-party port forwarding tool or a dedicated server hosting service for a more reliable multiplayer experience.\n\nUnderstanding Valheim''s multiplayer mechanics is crucial for troubleshooting. The game uses peer-to-peer connections for multiplayer, meaning the host''s device acts as the server. This setup requires a stable internet connection and proper network configuration. By following these steps, you can resolve the ''Port Forwarding Failed'' error and enjoy seamless multiplayer gameplay with your fellow Vikings.