dash home will work to some extent showing files and videos recently used but will not show apps also ubuntuu software centre will not open when clicked only get a grey screen

this bug only occurred recently having experienced problems with update manager which has recently been repaired.It seems to be connected with the ubuntu software centre which as outlined at the moment does not work in any shape what so ever.I only get a grey screen when I click on the app which I have unlocked from the desk top and now does not show.I have reloaded the software cenre through synapticbut can not get the app to show on the desk top.