Have exactly the same problem Just a blank screen, and in the sidebar no preview.. Can't logon because it displays nothing.. Thing is, it's only on my work-Win8 notebook.. My home win8 notebook has no issues with this.. Though that's a Intel GMA950 device, where at work I'm with a Radeon HD2600..
So the weird thing: It worked in the past. Somehow this bevaviour has popped up. Still get messages, but can't actually open the app. When I uninstall the app, and reinstall, the settings are retained! Still getting messages and everything, but same behaviour..
When I uninstall the app, it'