RE6 relies on specific Microsoft Visual C++ runtimes. If they are broken, the Steam API hook fails.
If Steam’s background service is damaged, a manual re-registration can help. how to fix failed to initialize steam resident evil 6
Right-click the Steam system tray icon → Exit . Then relaunch Steam as a standard user (do not use "Run as Administrator" yet). RE6 relies on specific Microsoft Visual C++ runtimes