What Causes CS:GO Failed to Connect to Match? The error is quite a broad one but you can always gather a couple of problems which happen to almost everyone: Broken or missing game files. Windows Firewall blocking the game from running.
Why does Steam say my game is running when its not?
One of the possible problems which can occur when you want to run a game through Steam is getting an error message saying “Failed to start the game (app already running). This problem occurs when your previous game failed to shut down properly or when you simply forgot to exit.
Why does Steam keep disconnecting?
Some users reported that while playing online on Steam, they are disconnected from the server. One of the best solutions is to update your video adapter driver using a reliable tool. You can also try flushing up your Steam and DNS configuration to fix the problem.