Real-time antivirus scans can intercept the game’s attempt to call the Steam process.
are allowed through your Windows Firewall or third-party antivirus software like Disable Overlays : Turn off the Steam Overlay in Steam > Settings > In-Game
This error typically appears when the game cannot connect to or verify the Steam client, even when Steam is running. Below are the most effective fixes, from simplest to most advanced.
Fully exit Steam. Do not just click the "X" in the corner. Right-click the Steam icon in your system tray (near the clock) and select "Exit" or "Quit Steam."