Irresponsive apps. Many of the apps cannot be launched

[WPCentral Question]

I cannot launch many of the apps of my lumia 920. They are totally irresponsive, including Calendar, games, music, facebook, weather, battery saver, etc. The live tiles of those apps are dead indeed and are not updating anymore. When I hit the apps they either just blink or the whole screen flips and nothing. I restarted the phone multiple times with no success. I also reinstalled some of the apps and they became responsive but some apps cannot be uninstalled like Calendar. Other apps that I reinstalled are now opening but the live tiles are not live and the do not show info.