League of Legends: How to fix the Unable to Connect to Authentication Server error

The error message "unable to connect to authentication service" has been received by many League of Legends players. The problem could be caused by a weak internet connection, a stuttering firewall, or a problem on Riot Games' end. The problem message will appear during champion choosing, on the login page, or about halfway through a game. Fortunately, there are options for players to resolve this issue. But first, a player should check Riot Games' Service Status page to determine if the server they're trying to access has had any recent troubles or reports. If the server is in good working order, the issue could be the Windows Firewall.

If a player's Windows Firewall isn't up to date, they may be unable to access the game properly. As a result, the gamer should either update their firewall or turn it off temporarily. The firewall settings can be found on the Windows Security page. Players can use the search box at the bottom of the dashboard to look for Windows Security. For the Domain Network, Private Network, and Public Network, players can disable the firewall.

Uninstalling and then reinstalling the game on the PC is another option for debugging. Whatever internal problem the game was having might be resolved with a complete restart. Turning the wi-fi on and off may also help to solve the problem. If none of these options work, players should contact Riot Games' customer service.