Launcher won't load / can't manually open a game

My launcher will not load, so I cannot open games from it. And, I find that I cannot now manually open games by selecting them from program files - they must be opened only through the launcher? The message I am getting is: “the Blizzard agent went to sleep. Attempting to wake it up.” Interestingly, it is just the games tab of the launcher. I can still access the shop page, etc.