Human Scale. Viewport Scale Reference
The figure is missing. What happened?
Click the button. Show starts off, and a new file starts off. If Figure is Custom FBX and no file has been chosen, nothing draws. After a reinstall, choose the FBX again. The built-in figures do not need that.
Why is my character the wrong height?
Height is the mesh as it stands in the file, from the lowest point to the highest. A crouch set to 1.8 m is 1.8 m in that pose. It does not stretch the character up to a standing height the pose does not have.
Why does the figure move when I orbit?
Offset is the left or right of the view, not a world axis. Orbiting keeps the feet beside the origin, on the side you picked. Set Offset to 0 and the feet sit on the origin.
Does it render?
No. It is drawn in the 3D Viewport only. It is not an object, so it is not in the outliner, and a render does not include it.