By James Philip
If you create a 3D Camera view and then change the view discipline. (See Figs 1 & 2)
Fig 1
Fig 2
Then when you return to the plan view you created it and then go to the browser and choose show camera, it does not reappear.
Fig 3
The only way to rectify this, is to change the 3D view discipline back to its original setting and then the camera reappears. (See Fig 3)