As a heads up to fellow devs, today is the second time a player on Steam has sent me this concern after a game update: “An Application Control policy has blocked this file.” I have a hard time figuring out exactly what triggered their “smart” app controls, but this work around took care of it for them both times:
1. Right-click the game and select Properties
2. Go to the Installed Files tab and click Verify integrity of game files.
3. Relaunch the game once the process completes.