Rainbow Six Siege Synchronization Failed: Fixes

If you see “Synchronization failed” in Rainbow Six Siege, it means the game could not connect to Ubisoft’s servers to verify your save data, which usually blocks you from playing online. This guide explains the common causes and the step-by-step fixes that resolve the error for most players.

What Does “Synchronization Failed” Mean in Siege?

Rainbow Six Siege stores your profile, settings, and progression on Ubisoft’s servers. When you launch the game, it attempts to sync that data with your local copy. If the connection is interrupted, times out, or the local file is corrupted, you get the synchronization error. It is not a problem with your internet speed or your computer’s hardware; it is a communication issue between your game client and Ubisoft’s servers.

Common Causes of the Error

Ubisoft server outage or maintenance: The most frequent cause. Check the official Ubisoft server status page before troubleshooting your own network.
Antivirus or firewall blocking the game: Security software can mistakenly block Siege’s connection to the server.
Corrupted local game files: A partial update or crash can leave your local save data out of sync.
VPN or proxy interference: A VPN can route your connection through a server that Ubisoft rejects.
Outdated game or Ubisoft Connect client: Running an old version can cause sync failures after a server-side update.

How to Fix Synchronization Failed (Step-by-Step)

Try these fixes in order. Most players resolve the issue with the first or second step.

Check Ubisoft server status. Visit the official Ubisoft server status page. If servers are down or under maintenance, wait and retry later.
Restart Ubisoft Connect and your PC. Fully close Ubisoft Connect (check the system tray), then restart it. If that doesn’t work, restart your computer.
Run Ubisoft Connect as administrator. Right-click the Ubisoft Connect shortcut and select “Run as administrator.” This can fix permission issues that block the sync.
Disable your VPN and proxy. Turn off any VPN or proxy service, then try launching the game again.
Add exceptions in your antivirus/firewall. Add the Siege executable (usually RainbowSix.exe) and Ubisoft Connect to your antivirus and firewall whitelist. Check your antivirus’s documentation for exact steps.
Verify game files. In Ubisoft Connect, go to your Games tab, click on Rainbow Six Siege, select Properties, then Verify Files. This checks and repairs corrupted files.
Clear the local save data (last resort). If nothing else works, you can delete the local save file to force a fresh download. This will not delete your online progress (which is server-side), but it will reset your local settings. Navigate to Documents\My Games\Rainbow Six - Siege and rename the folder to Rainbow Six - Siege_backup. Restart the game. It will create a new folder and download your settings from the server.

Why Does It Happen So Often?

Siege’s sync system is sensitive to any interruption during the handshake. Unlike some games that only sync at launch, Siege also syncs when you change settings or when the game updates. A common misconception is that a slow internet connection causes the error. In reality, a stable connection matters more than speed. Even a brief packet loss during the sync can trigger the failure. That’s why restarting your router or switching from Wi-Fi to a wired connection often helps.

What Not to Do

Don’t delete your “GameSettings.ini” file repeatedly. This file contains your graphics and control settings. Deleting it forces you to reconfigure everything and can cause further sync issues.
Don’t reinstall the game immediately. Reinstalling is time-consuming and rarely fixes a sync error caused by server or network issues.
Don’t use third-party “save editors” or mods. These can corrupt your save data and make sync failures permanent.

Comparing Sync Failed to Other Siege Errors

There are several similar errors in Siege. Knowing the difference helps you choose the right fix.

Synchronization failed: Profile/save data cannot sync. Fixes above.
Connection error (0x0000010b): General network failure. Usually fixed by restarting the game or router.
Server unreachable: The game cannot reach Ubisoft’s matchmaking servers. Check your internet connection.
Update failed: The game client cannot download a patch. Verify files or restart Ubisoft Connect.

Frequently Asked Questions

Will I lose my progress if I delete the local save file?

No. Your rank, operators, and cosmetics are stored on Ubisoft’s servers. Deleting the local folder only resets your settings (graphics, controls, audio). The game will re-download your profile from the server on the next launch.

Does the error happen on consoles too?

Yes, it can happen on PlayStation and Xbox as well. The fixes are similar: check server status, restart the console, and check your network connection. On console, you cannot verify files, but you can clear the local saved data from the console’s storage settings.

Why does it happen after every update?

Updates often change the game’s data structure. The sync process can fail if the update was interrupted or if the local files are from an older version. Verifying files after an update usually prevents this.

Can a VPN cause this error?

Yes. A VPN can make your connection appear to come from a different region, which can cause Ubisoft’s servers to reject the sync. Disable your VPN and try again. If you need a VPN for other reasons, try connecting to a server in your own country.

Is there a permanent fix?

There is no single permanent fix because the error has multiple causes. However, keeping your game and Ubisoft Connect updated, adding exceptions to your antivirus, and using a stable wired connection will prevent the error in most cases.

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