So you make a object put a canvus inside it then make it a prefab then later you go to edit the prefab and inside the prefab you cannot edit the canvus becouse it is not visable.
used to be fine, they make stuff shiner but take away our usability.
It seems some of your objects are disabled. Might that be the reason, or is there something else?
Also: your camera is disabled, maybe you should change that.