How to fix the “unexpected error with the login session” bug in LoL

Editor

Publish Date: January 13, 2025

LoL players trapped behind an error window that says “unexpected error with the login session” need look no further, as we have the solutions you need.

Developer Riot Games is known for offering a buggy and inconsistent experience to players using the League of Legends client, and this error is just another example of that trend. The error can be one of the most frustrating issues to encounter, appearing just after a player has tried to launch LoL from the Riot Games client and stopping them from advancing any further towards actually playing the game. Luckily, it’s also one of the easier errors to solve once you know what to look for. Here are a few key solutions that should help you out.

The “unexpected error with login session” message, unlike a lot of Riot Games’ errors in LoL, actually tells you the truth about what’s wrong upfront, as it correctly indicates some sort of miscommunication between Riot Games’ server and your computer. This leads to a failure to resolve the necessary authentication process of the login attempt.

While it can be frustrating to be stuck at this message, there are a few different solutions that can solve it.

With that context in mind, once you’re ready to resolve the “unexpected error with login session” message in League of Legends, here’s the first fix we would recommend:

Select the LoL client, then press Alt+F4. Choose “sign out” rather than “exit” when the client asks how you want to close it. That difference is important.
Open your Task Manager, then end all current League of Legends, League of Legends client, and Riot Games client processes.
Reopen the Riot Games client and try to launch League of Legends.

In most cases, this solution should be enough to get you up and running and again, bypassing the error message moving forward. This error is often caused by the League of Legends program running for too long and quietly de-authenticating its session with Riot Games’ servers during that time. But if it doesn’t work for you, there are a few more solutions to try:

Change the DNS server on your wireless router. For players unsure what a DNS server is, or how to change it, there’s are many of easy-to-follow DNS guides online.
Change the language settings in your League of Legends client. Many players encountering this error find that their default language has been inexplicably swapped. If this is the case, choose language in settings, and revert the language to whichever preferred language was being used before the change took place.
Try enabling your Virtual Private Network, or if you’re already using one, disable your VPN and then try accessing the Riot Games client once it has been turned off. If you’ve tried everything else and nothing seems to work, turning your VPN on or off may be successful for you.

If none of these solutions work, there’s likely something more complicated going on than can be resolved through following any broader guidance. Try filing a ticket directly with Riot Games Support, and consider using the Hextech Repair Tool to package game files into a .zip file for Riot to take a look at. That will go a long way towards helping their support staff to ascertain what exactly is going on with your Riot Games client and why you’re not able to access the League of Legends application.