Game Crashing/not opening

Whenever I enter a game, and then switch from the client onto another tab, I can't re-open the client, so I close it, but when I reconnect, the screen goes black, I'm told I can't connect to the server (retry), and then I sign out to fix the problem. I'm not trying to reconnect, but I've been waiting for a while and I haven't gotten past the loading of the client.