Error: Unfortunately, System UI has stopped

I have this appearing on my galaxy s4 after rooting (via CF-auto-root) (worked fine) and then in CWM ROM manager i tried flashing CWM superuser and then i wiped cache and rebooted to find this error message a black wallpaper/background instead of the original blue and the drop down tab (pull...

Error: Unfortunately, System UI has stopped

Error: Unfortunately, System UI has stopped