WordPress 4.0 Status : Published "Edit" Funcion

Having upgraded to WordPress 4.0, I find that I am now unable to adjust the Status : Published (Edit) function from “Published” to “Draft” which removes my post from public view. A campaign we have been running has just finished and I want to remove it from view for a while. Adjusting the status from “published” to “draft” allowed me to do this. But WordPress 4.0 seems not to allow this edit to be made.