Grey box surrounding the object

Portland

What's this grey box surrounding the object? It only appears in the shading view. I used Diffeo to do the importing. Is it necessary or can it be deleted/hide? Using Blender 3.6 LTS

 

Screenshot is from top-right side looking down.

 

Padone

That could be a iray skin if you're using eevee, will render fine with cycles. To render fine with eevee you can choose "skin method = sss" in the global settings, this way the iray skin will be approximated to a standard sss blender skin.