: Fully close Steam from the system tray (taskbar icons). Right-click the Steam icon and select "Run as administrator" .
: Verify that your antivirus software has not quarantined critical game files, such as steam_api64.dll . 3. Client-Side Software Fixes How To Fix Unable To Initialize Steam API Error just cause 4 unable to initialize steam api
The issue is usually Method 1 (corrupted file) or Method 3 (Windows permission issues in the Program Files folder). Try those first. : Fully close Steam from the system tray (taskbar icons)