I have recently opened after effects and I set up a new composition with a chosen background colour and I get a red screen in the whole of the comp window. This happens when also I open a recent composition. If I try and bring something into the composition, it still stays red. If I try to zoom in and out, still stays red. It has nothing to do with any video imports, I have emptied all my cache both manually and through purge - the whole composition window is red....just red. Any help would be gratefully received.