Why can't I adjust my model in Revit's 3D view?

I have the same problem since the first time i installed revit two month ago.
i can edit whatsover in elevation and plans but not in 3d view. ive confirmed that it is already in default 3d view
i can view it but nothing are able to be edited in that view. the rotation works just fine. can anyone solve this problem?

https://s16.postimg.org/oy2f6a0at/image.png

You need to select the default 3d View, this will allow you to edit.

Camera 3d views doesn't allow you to edit.

Any more vague and that wouldn't be a question :-)
What do you specifically mean?
One can do quite a lot of editing in 3D Isometric views!