: Right-click the Steam shortcut on your desktop and select "Run as administrator." Then, launch Just Cause 4 from your library.
When you run Just Cause 4 as an administrator, the game elevates its privileges. However, the Steam API runs at your standard user privilege level. The game, now running with higher privileges, cannot communicate with the lower-privilege Steam API process. The handshake fails. just cause 4 unable to initialize steam api
While the game itself offers great tethering mods and sandbox destruction, the technical polish is lacking. Once I finally bypassed the API issue, I still ran into frequent crashes and weird texture pop-ins. If you're looking for a smooth experience, you might want to stick with until this one gets more stability patches." How to Fix the Error : Right-click the Steam shortcut on your desktop