How To Fix Client Server Version Mismatch in League of Legends

If you’re seeing a client server version mismatch error in League of Legends, it usually means your game client and the server are not on the same version. This often happens after a new patch, when your client hasn’t updated properly or is out of sync with the current game version.

It can be frustrating because it stops you from logging in or playing normally, even though the issue is usually simple to fix. In most cases, it comes down to update problems, cached files, or connection issues during patching.

In this guide, you’ll learn what causes the client server mismatch error and the easiest ways to fix it so you can get back into the game quickly.

What Is the Client Server Version Mismatch Error in League of Legends?

The client server version mismatch error in League of Legends appears when your game client is not on the same patch as Riot’s servers. Since League of Legends is fully online, both sides must be running the exact same version for the game to work.

This usually happens for a few common reasons. Your client might be outdated, the update may not have installed correctly, or the servers have already moved to a newer patch while your game hasn’t caught up yet.

When this mismatch happens, the game blocks access completely. You won’t be able to queue or log in properly until your client matches the server version.

In simple terms, it’s a sync issue between your game and Riot’s servers, and fixing it means making sure your client is fully updated and aligned with the current patch.

How To Fix Client Server Version Mismatch

If you’re getting the client server version mismatch error in League of Legends, it means your game isn’t synced with Riot’s current patch. The fixes are usually simple and focus on updating or refreshing your client.

1. Restart the League Client

Start with the easiest fix. Close the client completely and reopen it.

Sometimes the update just didn’t trigger properly, and restarting forces the client to check for the latest version again.

2. Check for Updates Manually

If the game didn’t update automatically, you need to trigger it.

Open the Riot Client and make sure League of Legends is downloading the latest patch. If you see an update button or progress bar, let it finish before trying to log in.

3. Log Out and Back In

Logging out refreshes your connection to Riot’s servers.

Sign out of the Riot Client, close it, then reopen and log back in. This can fix sync issues between your account and the current patch.

4. Use the Repair Tool

Hextech Repair Tool can fix files that didn’t update correctly.

Run it as administrator and select the repair or repatch option. It will scan your game files and replace anything missing or broken.

5. Delete Patch Cache Files

Sometimes old patch data causes conflicts. Clearing it forces a fresh update.

Go to your League of Legends folder and remove temporary patch files or cache folders, then relaunch the client so it downloads everything again.

6. Check Server Status

There are times when the issue isn’t on your side.

If Riot servers are updating or under maintenance, you may see this error until everything is fully synced. Waiting a bit and trying again later often fixes it.

7. Reinstall League of Legends

If nothing else works, reinstalling the game is the final step.

Uninstall League of Legends, download the latest version, and install it again. This ensures you’re on the correct patch with clean files.

In most cases, restarting the client or finishing the update solves the problem. The error mainly happens when your game is out of sync, so the goal is always to get your client fully updated to match the servers.

Conclusion

The client server version mismatch error in League of Legends is usually caused by your game being out of sync with Riot’s servers. While it can stop you from playing, the fixes are straightforward and don’t take much time.

In most cases, restarting the client, completing updates, or using the repair tool will solve the issue quickly. More advanced steps like clearing cache or reinstalling are only needed if the problem persists.

As long as your client is fully updated and properly synced, the error won’t come back. Once fixed, you can get back into the game without any further issues.