I’m not sure what happened or when, but I know that I used to be able to rotate the Editor view by dragging with the right mouse button. Now, in 4.5, it pans the camera. Is this a bug or did they change this, and why?
Make sure the ‘2D’ button is not pushed in the scene window’s ‘tool bar’
To reset the Scene view - hold SHIFT and Left click on the CENTRE BOX - of the X-Y gizmo in the scene. (top right corner)