How to Fix ‘There Was an Unexpected Error With the Login Session’ in League of Legends

Quick Fix

This is Riot's own official fix, and it works for most players:

1. Press Alt+F4 while the League client is open, then choose Sign Out (not Exit).
2. Open Task Manager (Ctrl+Shift+Esc) and end every instance of RiotClientServices.exe and LeagueofLegends.exe.
3. Reopen the Riot Client, launch League of Legends again, and log back in.

Step-by-Step Guide

What this error means

The message 'There was an unexpected error with the login session. Please try again' shows up when the League of Legends client loses sync with Riot's authentication servers. According to Riot's own support article and multiple gaming outlets, this typically happens because leftover Riot/League processes are still running in the background after a previous session, confusing the new login attempt. It can also be triggered by network issues, DNS problems, VPNs, firewall blocks, or an unexpected client language change. It is rarely a sign your account is banned or compromised — it is almost always a client/network glitch.

Fix 1: Sign out properly and kill leftover processes (official Riot fix)

1. Close via Sign Out, not Exit. With the League client open, press Alt+F4. When prompted, click Sign Out rather than Exit — this properly ends your login session instead of just closing the window.
2. Open Task Manager. Press Ctrl+Shift+Esc, go to the Processes tab, and look for any running instances of RiotClientServices.exe and LeagueofLegends.exe.
3. End every instance. Right-click each one and select End Task until none remain in the list.
4. Relaunch and log in. Reopen the Riot Client, start League of Legends, and log in again. This resolves the issue for the vast majority of players, as it clears out any stuck session data left behind after the client was running for a long time.

Fix 2: Reset your network and check your VPN

1. Restart your router and PC. Power off your router or modem for 1–2 minutes, then restart your computer to clear temporary network glitches before relaunching LoL.
2. Disable any VPN. If you use a VPN, turn it off and try logging in without it. If you were not using one, some players have fixed the error by temporarily enabling a VPN instead, so it is worth testing both ways.
3. Change your DNS server. Some players have found that switching their DNS server address resolves the login mismatch. On Windows, go to Network Settings > Change adapter options, right-click your connection, open Properties > Internet Protocol Version 4 (TCP/IPv4), and set a public DNS (such as 8.8.8.8 / 8.8.4.4).
4. Check your firewall. Open Windows Firewall > Allow an app through Windows Firewall > Change settings, find League of Legends and the Riot Client in the list, and make sure both are checked and allowed.

Fix 3: Check the client language and Riot server status

1. Check the client's language setting. Some players have found their League client's language had unexpectedly changed right before this error appeared. Revert it to your normal language in the client settings and relaunch.
2. Check Riot's server status page. This error can also occur when Riot's login servers are overloaded or experiencing an outage. Visit the official Riot Games server status page for League of Legends and your region to see if there are known issues — if so, you'll just need to wait it out.

Fix 4: Repair or reinstall the client

1. Run the Hextech Repair Tool. Riot provides this official tool to fix corrupted client files. Download it from Riot's support site, run it, and choose the repair option for League of Legends.
2. Reinstall as a last resort. If the repair tool does not help, uninstall League of Legends via Control Panel > Programs and reinstall using the latest installer from the official League of Legends website.

When to contact Riot Support directly

1. File a support ticket. If none of the above works, submit a ticket through Riot Games' official support page, and consider attaching the Hextech Repair Tool's generated .zip log file so Riot support staff can diagnose deeper account or server-side issues.
2. Note the platform. These steps are for the Windows and Mac PC client; there is no mobile or console version of League of Legends, so this error is desktop-specific.