Here is what you need to do to get the 3D perspective view back:
Go to the plan view of your model
Go to View > 3D View Mode > 3D Projection Settings to edit the perspective settings (not parallel projections).
On the left of the window, you will see the plan of the model.
Press Alt on the keyboard and click to place target.
Press Shift on the keyboard and click on the plan to place the camera.
Try to place both on or close to the model plan.
On the right side of the window, where it says "Camera Z" and "Target Z", make sure the values are similar and positive.
If you go to 3D Generic Perspective now, you will hopefully see your model!
It worked for me