Then download the installation file from the website.
Lastly, if none of the above solutions solve the League of Legends client not opening issue, then you can choose to uninstall and reinstall the game. This is one of the best solutions that can be used to fix the League won’t open issue. If the above solution does not work then you can make some modifications in the League of Legends Client to fix the issue.
Method 4: Modify the League of Legends Client Also, you can right-click on it and then select the option “Run as Administrator”.