Editor not rendering scene, camera or shader problems?

As you can see, my scene is not appearing in the scene view at all, but is rendering on the camera. When I make a build the screen is black, and the GUI HUD camera also renders black which may well be blocking the standard camera. Any one got any suggestions? I have updated the editor from 2018.3 to 2019.1.5f1, nothing else has been changed so I can assume at the moment that this is a bug, has anyone else had or solved this issue? Thanks for any help!