Why does my phone say "System UI has stopped" ? .... more in description

[AC Question]

Yesterday I updated my Samsung Galaxy Note 3 after I received a notification that a system update what available ( update 10.0 ) - when my device restarted after the update, there was no lock screen ( it immediately went to my homescreen ), the homescreen wallpaper was black, and there was no notification bar at the top of my screen. The update was successful though- my apps are updated ( such as the Messaging and etc. ) with the new look of the 10.0 update. Yet, I cannot answer phone calls, no box pops up on my screen when someone calls, although my ringtone plays. I receive the messages "Unfortunately System UI has stopped", and "Unfortunately Package Access Helper has stopped". I have tried clearing the cache in my settings>application manager- however the box is gray and will not let me click it. My phone is not rooted, and does not have a virus, it has been scanned by lookout, and any potentially harmful apps have been removed. I had not gotten any new applications before the update, nothing had been changed except the fact that I got the update. Please HELP !!!!

Any help would be extremely necessary!!!!