Instead of downloading a random file, use these official methods to restore the DLL: Verify Game Files (Steam): Right-click Resident Evil 6 in your Steam Library. Properties Installed Files Verify integrity of game files . Steam will automatically detect the missing and download the official, safe version. Check Your Antivirus Quarantine: Sometimes antivirus software flags steam_api.dll

Those sites (dll-files.com, dll下载中心, etc.) often provide:

To fix the "steam_api.dll is missing" error for Resident Evil 6