If you’re stuck trying to get your League client started because you keep being told ‘Another Instance of the Launcher is running’ – no worries! It’s actually a very easy fix. This usually happens when your client either didn’t start properly or didn’t close properly, neither of which are that unexpected because the League of Legends client is notoriously buggy and laggy.
Also read: League of Legends Flex Queue Rank Distribution
Windows
You’re gonna want to open the task manager, either by right-clicking the taskbar and clicking ‘Open Task Manager’ or by pressing CTRL+ALT+Delete and choosing ‘Open Task Manager’ from the menu that it prompts. Then, you’ll want to look for LeagueClient.exe, right-click it, and click ‘End Process.’
Now, if you try again you should be able to boot the League of Legends client now that you’ve ended the previous instance in your task manager.
Mac
First, you’ll want to try the tried and true classic – right-click the icon in the dock and click ‘Force Quit’ – this should end the process.
If this doesn’t work, however, you’ll want to try opening the Activity Monitor (Command+Space to open spotlight, then typing in ‘Activity Monitor’ and pressing enter is the fastest. You can also find it in your Applications folder in Finder though) – then you’ll want to find the League client process, select it, and click the X icon above the list. This will kill the process.
