Ok since most people are having troubles with their White Hallway key, by it saying "Your connection is freaky out." The way you start the mission is click N, Choose your normal mission contact(Agent gray..etc.) Click to download the mission. Once it gives you the details for the mission, now right click on your key and Click "Use item" and it should work now. Also in the key details it said they can be used downtown, not sure if that's true or not but you might as well just actived the key there.
I hope this helps and answers your questions. 
