Dark Grey Sky Without Sun After Changing Texture Pack Back To Default

When i was playing on my red stone flat map i changed texture pack to something else. Than back to normal and my sun faded away when sky turned gray. Quiting and playing same map again helped and turned sun back on. I can do it as many times as i want but only on this save, Creating another map with the same settings doesnt bug. Re-Creating doesnt copy the bug. I can send save somehow.