Valorant Error van-51 means Riot Vanguard found software on your system that conflicts with its anti-cheat layer. Common culprits include certain VPN drivers, cheat-detection bypass tools, unsigned kernel drivers, and some low-level system utilities.
Usually client-sideLast verified: 2026-08-19
Identify the conflicting software
Vanguard's error sometimes shows the conflicting process name. Close all background applications — particularly VPN clients, third-party antivirus with kernel components, and system tuning tools. Then restart your PC and try again.
Driver conflict
Some hardware driver updates introduce kernel-mode code that Vanguard flags. If the error appeared after a recent driver or software installation, roll back or uninstall the newly installed software.
How to fix step by step
- 1Close all non-essential background applications, especially VPN clients and third-party antivirus
- 2Restart your PC completely — do not just restart Valorant
- 3If the error appeared after a recent install, uninstall the most recently added software or driver
- 4Check the Valorant support site for the current list of applications known to conflict with Vanguard
How VAN-51 differs from related codes
- Error VAN-81: Valorant lost connection to Riot services during login or queue. (server or client)
- Error VAN-1: Vanguard, Valorant's anti-cheat system, is not running or failed to initialize, so your client is not authorized to launch a match. (user-side)
- Error VAN-9003: Valorant could not connect to Riot services or complete Vanguard checks. (server or client)