Well if you have the 3D of this assembly, you can directly explode as you wish, see the configuration tab... Then in your MEP you have inserted your view, so you right-click in your property view and click on exploded view... I'll take screenshots as soon as my pc is available... Or else watch this => Bing videos Good luck. @+. AR.
Usually when this error appears it is because the corresponding properties do not exist in the file, in this case the asm file of the subassembly. So I'd look at the custom properties of the 3D of the subassembly. The plan model with indications in the cartouche on the material, the treatment, a surface condition seems well suited for a part, less so for an assembly. Maybe you used the wrong document template for your drawing?