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If League of Legends will not open, first check Riot’s service-status page, then work through Riot Client’s Repair tool, cache cleanup, a Windows clean boot, security-software exceptions, graphics-driver updates, and Vanguard requirements. Reinstall League and Vanguard only after those lower-impact checks. The correct fix depends on where startup stops: before Riot Client, at the Play button, before the loading screen, or after champion selection.
Identify exactly where launch fails
Note the last thing you see before trying a fix. A client that never appears points to Riot Client, Windows, or a background-process problem. A client that opens but does nothing after Play often involves damaged files, permissions, security software, or Vanguard. Closing during the transition to the game can indicate graphics software or a firewall rule. A failure after champion selection has a dedicated Riot checklist with executable exceptions and compatibility settings.
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| Where startup stops | What it commonly indicates | Start with |
|---|---|---|
| Riot Client never opens | Windows process, cache, security software, or a service issue | Check service status, close stuck processes, then clear local caches and clean-boot Windows |
| Riot Client opens, but Play does nothing | Damaged game files, permissions, firewall/antivirus filtering, or Vanguard | Use Repair, add the documented exceptions, and verify Vanguard and Windows updates |
| Game closes before the loading screen | Graphics driver, compatibility mode, security software, or Vanguard | Update the graphics driver, disable compatibility mode, and check Vanguard |
| Game closes or fails after champion selection | One of the League, Riot Client, or Vanguard executables is blocked or altered | Apply the complete exception list, run Repair, clear caches, and then reinstall if necessary |
| Several players cannot connect at once | A Riot service incident rather than one PC | Check Riot Games Service Status before changing local files |
1. Check Riot’s service status before changing Windows
Open Riot Games Service Status and look for an incident affecting League of Legends, login, matchmaking, or the game platform. A live outage can look like a local launch failure. The status page used for Riot’s current guidance is JavaScript-based, so an empty or unreadable incident list does not prove that no incident exists; compare the behavior with another player or try again later if multiple people are affected.
If the problem occurs only on your computer and other players are launching normally, continue with the local steps below. Record any visible VAN code or exact error text before closing the client.
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2. Repair League from Riot Client
Riot’s documented repair path is the least disruptive file check and should come before a reinstall.
- Open Riot Client and sign in.
- Select the Settings icon.
- Choose League of Legends in the left column.
- Click Repair and let the process finish without launching another copy of the game.
- Restart Riot Client and try Play again.
Repair can replace or restore damaged game elements, but it cannot correct a blocked executable, an outdated graphics driver, or a Windows/Vanguard requirement. Continue to the relevant section if the button completes without changing the symptom.
3. Clear Riot and League’s local caches
Stale or corrupted files in the per-user cache can prevent the client from handing off to the game. Riot’s general launch guide calls for removing the game folders under your local application-data directory and then checking Riot Games for a game folder.
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- Exit Riot Client and League. In Task Manager, end any remaining Riot Client, League, or LeagueClient processes so Windows is not holding files open.
- Open File Explorer and enter
C:Users<you>AppDataLocalin the address bar. Replace<you>with your Windows account name. AppData is hidden by default, but typing the path opens it directly. - Delete the League of Legends game folder shown there.
- Open the
Riot Gamesfolder in the same location and delete any League game folder inside it, as Riot’s guide instructs. - Restart Windows, open Riot Client, and test the launch.
Do not remove unrelated personal folders. If Windows says a file is in use, reboot and repeat the deletion before moving on.
4. Isolate background-process and security conflicts
Riot says background processes can fight with League. A clean boot starts Windows with nonessential services and startup programs suppressed, making it possible to identify a conflict without permanently uninstalling software.
Perform a Windows clean boot
- Press
Win+R, typemsconfig, and press Enter. - Open the Services tab, select Hide all Microsoft services, then click Disable all.
- Open the Startup tab and choose Open Task Manager. Disable enabled third-party startup items.
- Close Task Manager, click OK in System Configuration, and restart Windows.
- Launch Riot Client and League. If the game works, re-enable services and startup items in small groups, restarting between groups, until the conflicting program is identified.
Security software can still interfere even during a clean boot. Rather than leaving protection disabled, add exceptions for the specific executables Riot lists. The exact installation folder can differ, so use a Riot Client shortcut or the file location shown in Task Manager to select the real files on your PC.
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Add the documented exceptions
Add the following files to your firewall and antivirus allowlists, including both the League and Vanguard components:
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After saving the rules, restart Riot Client and test again. If your security product cannot create exceptions, Riot’s champion-selection guide suggests temporarily disabling or uninstalling it only to identify whether it is the conflict. Disconnect from untrusted networks while protection is disabled, test briefly, then restore or reinstall the security product immediately.
5. Update the graphics driver and remove compatibility overrides
League can close during the handoff from the client to the game when the graphics driver is outdated or when Windows is forcing an old compatibility profile.
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Install the current graphics driver
Get the driver for your GPU from the graphics manufacturer’s official update channel. Choose the model that actually appears in Device Manager, install the current package, and restart Windows even if the installer does not insist on a reboot. Laptop owners should check whether their manufacturer supplies a customized driver for the system.
Turn off compatibility mode
- Find the League game executable, right-click it, and choose Properties.
- Open the Compatibility tab.
- Clear Run this program in compatibility mode for: and apply the change.
- Repeat for a Riot or League shortcut if that shortcut has its own compatibility setting, then relaunch through Riot Client.
6. Verify Vanguard and Windows requirements
Vanguard is not an optional add-on for League. Riot describes it as having a client and a kernel-mode driver and states: “Riot Vanguard must be active during League of Legends gameplay and any time the League Client is open.” If Vanguard is disabled or not running, League will not start normally.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Fix the driver behind crashes, sound loss and screen glitches3Clear out junk files and repair common Windows errorsWhen a VAN error appears
Write down the complete VAN code rather than guessing at a fix. Riot maintains separate error-code guidance, and the correct action depends on that code. Do not remove Vanguard as a first step; doing so prevents League from running until Vanguard is installed again.
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Install Windows updates and perform a full reboot
- Open Settings > Windows Update.
- Install all required updates, including any restart-pending update.
- Choose Restart, not merely Sign out or Shut down. A full reboot lets Vanguard’s driver load again.
- Open Riot Client after Windows returns and test League.
Riot’s Vanguard guidance specifically requires completing relevant Windows Updates and then fully rebooting after applying an error fix. If you disabled Vanguard, restart Windows before trying to play again; uninstalling it requires a reinstall before League can run.
7. Reinstall League and Vanguard only as the final local reset
Use a clean reinstall after Repair, cache cleanup, security checks, driver work, and Windows/Vanguard updates have failed. Reinstalling first can erase useful evidence and does not solve a blocked firewall rule or an unresolved driver problem.
- Close Riot Client and League processes.
- In Settings > Apps > Installed apps, uninstall League of Legends and Riot Vanguard when both entries are present.
- Restart Windows.
- Install the current League installer from Riot’s official site, allow Vanguard to install when prompted, and restart again if requested.
- Open Riot Client, let all game and Vanguard updates complete, and test a practice game before joining a live match.
If Vanguard does not reinstall or a VAN code returns immediately, stop repeating the uninstall cycle and use the matching Riot error-code instructions. A reinstall cannot substitute for the required Windows reboot.
8. If League fails specifically after champion selection
Riot’s dedicated champion-selection checklist combines several of the steps above. Confirm that every executable in the exception list is allowed, compatibility mode is off, and Riot Client’s Repair button has completed. Then clear the local caches, restart Windows, and test again. This sequence targets the point at which the client launches the game process and Vanguard begins enforcing its requirements.
9. When to contact Riot Support
Submit a Riot Support ticket after the documented checklist fails. Include:
- The exact stage of failure and whether Riot Client remains open.
- The complete error message or VAN code, copied exactly.
- Your Windows edition and version.
- Your GPU model and installed driver version.
- Whether other players can launch normally.
- Which steps you completed: Repair, cache removal, clean boot, exceptions, driver update, Windows update/reboot, and reinstall.
This information helps support distinguish a service incident from a local configuration problem and prevents you from being sent through the same steps again.
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