At the attempt to render camera views from cameras in a Maya scene file with the Arnold render view, the cameras are missing from the available cameras rollout menu in the Arnold render view.
Cameras are assigned to hidden display layers.
- Check if cameras are assigned to display layers.
- Remove the assigned cameras from the display layers or set the display layers to visible.
Note: It is not recommended to control the visibility of cameras by display layers. The camera object visibility can be controlled by selecting the camera in the Outliner and un-checking the function Object Display > Visibility in the Maya Attribute Editor: