Why can't I view the current players in my game whenever I play Team Fortress 2?

I click shift + tab to view the steam window, and then I click view players, so I can add friends or see their profile. But instead of seeing the players on that server, I get a message that reads, "No Steam users reported by game server." This has only started recently, about the time the Uber Update came. Has this happened to anybody else, and HOW DO I FIX IT SO I CAN VIEW THE PROFILES OF PEOPLE IN MY CURRENT GAME AGAIN?