Following the release of update 25.15 in League of Legends, some users have encountered a significant issue — the game fails to launch or update due to blocking by antivirus software. Riot Games has confirmed the existence of this bug, but it has yet to be fully resolved.

What is Known About the Issue

According to the developers, the culprit is the interaction between the game client and certain antivirus programs, which perceive the new League of Legends files as potentially dangerous. As a result, update or launch processes may be automatically blocked.

The most effective temporary solution at the moment is to add a series of files to your antivirus exclusion list. Riot Games advises accessing the antivirus settings section, often labeled "Advanced Threat Defense", and adding the following files:

• C:\Riot Games\League of Legends\LeagueClient.exe
• C:\Riot Games\League of Legends\LeagueClientUx.exe
• C:\Riot Games\League of Legends\LeagueClientUxRenderer.exe
• C:\Riot Games\League of Legends\Game\League of Legends.exe
• C:\Riot Games\Riot Client\RiotClientServices.exe
• C:\Program Files\Riot Vanguard\vgc.exe
• C:\Program Files\Riot Vanguard\vgm.exe

Important: If you installed the game in a non-standard location, ensure you specify the correct file paths.

How to Bypass the Blocking

After adding the files to exclusions, launch the game. If it doesn't open, check that none of the above files are running in compatibility mode. You can do this through the file properties: right-click on the file, open the "Compatibility" tab, and uncheck all boxes.

If the game still doesn't launch after this, Riot recommends temporarily disabling your antivirus. For safety, it's better to activate Windows Defender — according to the developers, it is compatible with the new patch and does not block the game.

As a last resort, Riot advises using the Riot Repair Tool — a utility for collecting logs and subsequently sending a request to support. Specific timelines for a complete fix have not yet been announced, but developers are actively working on resolving the issue.