Dead zone of visability

When rotating part of my model disappears as though sliced by an invisible plane. Have closed and reopened and it still occurs. Pretty worried since a lot depends on getting this work in to Layout this weekend. Appreciate hearing of a solution. Thanks.

Do a search for clipping plane. You’ll find a lot of information.

Key things:

Make sure the model isn’t too far from the origin.
Set the camera to Perspective and use Zoom Extents to back the camera out from the model. Generally it’s easier to work in Perspective mode anyway.