Valorant's error code 57 indicates a problem with Riot's Vanguard Anti-Cheat and is easy to fix (Image via Riot Games) ...

Unfortunately, Vanguard can come into conflict with the game from time to time, resulting to certain errors, one of which is the error code 57.

The primary problem could be with Riot's anti-cheat system, Vanguard. If it does not initialize properly, players are likely to come across the error code 57.