This is the most common solution. Completely exit Steam from the system tray and relaunch it.
Overzealous antivirus software (including Windows Defender) can quarantine or block Steam’s ability to trigger the game’s executable. This is especially common with ransomware protection. Resident evil 6 black box error failed to initialize steam
: Critical game files are missing or damaged. This is the most common solution
: Technologies like NVIDIA G-Sync or high CPU core counts on newer processors can cause this older title to fail. Resident evil 6 black box error failed to initialize steam