If League of Legends says, “There was an unexpected error with the login session. Please try again,” Riot’s recommended fix is to sign out, close every Riot and League client process in Windows Task Manager, then reopen the client and log in again. If that does not work, Riot says to check for and close KillerServiceNetwork.exe if it is running.
Fix the League of Legends login-session error
Follow Riot’s steps for the exact message “There was an unexpected error with the login session. Please try again.” These instructions are from Riot Games Player Support’s article dated May 31, 2026.
- Sign out of the client: With the League client open, press Alt+F4. When prompted, choose Sign out, not Exit.
- End the leftover processes: Press Ctrl+Shift+Esc to open Task Manager. Find and close every instance of
RiotClientServices.exeandLeagueofLegends.exe. - Start a fresh login: Reopen the League of Legends or Riot Games client, then sign in again.
Riot’s error-code reference says this message tends to happen when another League client instance is stuck running in the background. Ending all the named processes clears those instances before you try a new login; it is Riot’s likely explanation, not a confirmed diagnosis for every PC. Riot’s exact-error instructions and error-code reference give the procedure and explanation.
If the first attempt does not work
Check for KillerServiceNetwork.exe
Repeat the sign-out and process-cleanup sequence. If KillerServiceNetwork.exe appears in Task Manager, close it as well, then reopen the client and try to log in. Riot describes this as a conditional step: the program may prioritize bandwidth for online streams and reduce bandwidth for League, potentially contributing to disconnection. Do not remove unrelated network software based on this advice.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
#1 Best Overall
- Designed to inspire, chosen for champions: Take your game to the next level with the proven precision of Logitech G PRO Wireless Gaming Mouse, crafted to inspire League of Legends players
- LIGHTSPEED wireless: Pro grade performance overcomes the traditional limitations of wireless latency, connectivity, and power to deliver super-fast 1 ms report rate connection
- HERO 25K sensor: Delivers peak performance at any sensitivity with zero smoothing, acceleration, or filtering; the computer mouse is optimized to track insane flicks at speeds over 400 IPS
- Ultra-lightweight: The mouse's innovative endoskeleton creates a super-thin yet incredibly strong outer shell, enabling the body to weigh in at a lightweight and maneuverable 2.8 oz (80 g)
- Ergonomic ambidextrous design: Tournament-ready gaming mouse developed with esports pros and gamers for maximum comfort, control and durability
Confirm that the message is the same one
Riot lists “Unexpected Login Error” separately from “There was an unexpected error with the login session. Please try again.” Its reference associates the former with an unstable internet connection and gives different guidance, including restarting the router and changing DNS. Those steps are not Riot’s lead fix for the login-session message covered here. If your wording is different, use the entry for that specific error in Riot’s error-code reference.
Escalate a persistent exact-message error
Riot’s exact-error article does not set out a broader escalation procedure. Community reports include players for whom the steps did not help, so the process cleanup is not guaranteed to resolve every case. If the exact message remains after trying the official steps, check Riot’s current support and service-status channels or submit a request through Riot Player Support. A user report that an issue cleared after maintenance is an anecdote, not evidence that a server incident is underway.
Quick Recap
Best Value
- HERO Gaming Sensor: Next generation HERO mouse sensor delivers precision tracking up to 25600 DPI with zero smoothing, filtering or acceleration
- 11 programmable buttons and dual mode hyper-fast scroll wheel: The Logitech wired gaming mouse gives you fully customizable control over your gameplay
- Adjustable weights: Match your playing style. Arrange up to five 3.6 g weights for a personalized weight and balance configuration
- LIGHTSYNC technology: Logitech G LIGHTSYNC technology provides fully customizable RGB lighting that can also synchronize with your gaming (requires Logitech Gaming Software)
- Mechanical Switch Button Tensioning: A metal spring tensioning system and metal pivot hinges are built into left and right computer gaming mouse buttons for a crisp, clean click feel with rapid click feedback
Rank #4
- Next-gen 12,000 DPI HERO optical sensor delivers unrivaled gaming performance, accuracy and power efficiency
- Advanced LIGHTSPEED wireless gaming mouse for super-fast 1 ms response time and faster than wired performance
- Ultra-long battery life gives you up to 250 hours of continuous gaming on a single AA battery
- Lightweight mechanical design and classic shape for maximum maneuverability, durability and comfort
- Compact, portable design with convenient built-in storage for included USB wireless receiver
Rank #3
- The next-generation optical HERO sensor delivers incredible performance and up to 10x the power efficiency over previous generations, with 400 IPS precision and up to 12,000 DPI sensitivity
- Ultra-fast LIGHTSPEED wireless technology gives you a lag-free gaming experience, delivering incredible responsiveness and reliability with 1 ms report rate for competition-level performance
- G305 wireless mouse boasts an incredible 250 hours of continuous gameplay on just 1 AA battery; switch to Endurance mode via Logitech G HUB software and extend battery life up to 9 months
- Wireless does not have to mean heavy, G305 lightweight mouse provides high maneuverability coming in at only 3.4 oz thanks to efficient lightweight mechanical design and ultra-efficient battery usage
- The durable, compact design with built-in nano receiver storage makes G305 not just a great portable desktop mouse, but also a great laptop travel companion, use with a gaming laptop and play anywhere
Rank #2
- Designed to inspire, chosen for champions: Take your game to the next level with the proven precision of Logitech G PRO Wireless Gaming Mouse, crafted to inspire League of Legends players
- LIGHTSPEED wireless: Pro grade performance overcomes the traditional limitations of wireless latency, connectivity, and power to deliver super-fast 1 ms report rate connection
- HERO 25K sensor: Delivers peak performance at any sensitivity with zero smoothing, acceleration, or filtering; the computer mouse is optimized to track insane flicks at speeds over 400 IPS
- Ultra-lightweight: The mouse's innovative endoskeleton creates a super-thin yet incredibly strong outer shell, enabling the body to weigh in at a lightweight and maneuverable 2.8 oz (80 g)
- Ergonomic ambidextrous design: Tournament-ready gaming mouse developed with esports pros and gamers for maximum comfort, control and durability
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.
