Corrupted or missing files can prevent the game from recognizing the Steam API. Open your Steam Library. Right-click on Resident Evil 6 and select Properties . Navigate to the Installed Files (or Local Files ) tab.
Go to the game's local files, right-click , and select Properties . In the Compatibility tab: resident evil 6 fatal error failed to initialize steam top
Also disable Steam’s own overlay temporarily: Corrupted or missing files can prevent the game