I have fixed Vanguard Code 148 in League of Legends multiple times.
Here are the solutions that work:
- Reinstall Vanguard: Uninstall Vanguard from your PC. Open Riot Client. Follow the prompt to install Vanguard again. Launch League of Legends.
- Set Correct Permissions: Right-click League of Legends. Click Properties. Go to Security tab. Click on your Windows user account. Check all permission boxes to Allow. Click Apply.
- Check Game Location: Right-click League of Legends. Select Properties. Click Shortcut tab. Verify the target location exists. Click Apply.
- Remove Read-Only Status: Right-click League of Legends. Click Properties. Open General tab. Uncheck Read-only box. Click Apply.
- Create Fresh Shortcut: Navigate to League of Legends installation folder (Usually C:\Program Files). Find the game executable. Right-click and select Create shortcut. Move new shortcut to desktop. Delete old shortcut.
If these solutions don't work, run League of Legends as administrator. Try each fix in order until the error resolves.
