How do I troubleshoot the "World Save Sync Failed" error?

The ''World Save Sync Failed'' error in Valheim is a common multiplayer issue that occurs when the game fails to synchronize world data between the host and other players. This error can disrupt gameplay, causing progress loss or preventing players from joining the server. Understanding the mechanics behind world saving and synchronization is key to resolving this issue.\n\nValheim uses a host-based multiplayer system, where one player acts as the server (host) and others connect to it. The host''s world file is the primary source of truth, and all players rely on it for synchronization. If the host''s world file becomes corrupted, mismatched, or inaccessible, the ''World Save Sync Failed'' error can occur. This often happens due to network instability, file corruption, or mismatched game versions.\n\nTo troubleshoot this error, start by ensuring all players are using the same version of Valheim. Mismatched versions can cause synchronization issues. Check for updates on Steam or your preferred platform and verify that everyone has installed the latest patch. If the issue persists, the host should verify the integrity of their game files. On Steam, this can be done by right-clicking Valheim in the library, selecting ''Properties,'' navigating to the ''Local Files'' tab, and clicking ''Verify Integrity of Game Files.''\n\nIf the error persists, the host should check their world file for corruption. Navigate to the Valheim save folder, typically located in ''C:\Users\[YourUsername]\AppData\LocalLow\IronGate\Valheim\worlds'' on Windows. Look for the world file associated with the server (it will have the same name as the world). If the file is unusually small or missing, it may be corrupted. In this case, restore a backup if available. Valheim automatically creates backups in the same folder, labeled with a ''.old'' extension. Rename the backup file to replace the corrupted one.\n\nNetwork issues can also cause synchronization errors. Ensure the host has a stable internet connection and sufficient upload bandwidth. If the host is using Wi-Fi, switching to a wired connection can improve stability. Additionally, check for firewall or antivirus software blocking Valheim''s network access. Temporarily disabling these programs or adding Valheim to the exception list can resolve connectivity issues.\n\nFor players experiencing the error when joining the server, try restarting the game and reconnecting. If the problem persists, ask the host to restart their game and server. Sometimes, a simple restart can resolve temporary synchronization glitches. If the host is using a dedicated server, ensure the server software is up to date and properly configured.\n\nIn some cases, the error may be caused by mods or custom content. If the server or players are using mods, ensure all mods are compatible with the current game version and synchronized across all players. Mismatched or outdated mods can cause synchronization failures. Disabling mods temporarily can help identify if they are the root cause.\n\nFinally, if none of the above solutions work, consider creating a new world and transferring progress. While this is a last resort, it can resolve persistent synchronization issues. Use console commands or mods to replicate your progress in the new world, ensuring a fresh start without corrupted files.\n\nTo prevent future synchronization errors, regularly back up your world files. Manually copy the world files to a separate location or use a backup tool. Additionally, avoid abrupt disconnections or shutting down the game while saving, as this can corrupt files. By following these steps, you can troubleshoot and resolve the ''World Save Sync Failed'' error, ensuring a smooth multiplayer experience in Valheim.