Share 'infinite groundplane I can`t delete!'

Hello again, I have a strange infinite groundplane that I want to to delete but tried everything I know. In the blockmanager i was able to delete it but its still there! how can I get rid off it?? I don`t have a gi environment.. only a basic environment with dark grey background. GI enabled and skylight off. Since I deleted the plane in the blockmanager I created a new groundplane that isn't inv…