This smells like one of two things:
- There is a material issue with the character. Maybe missing image files. You could figure that out by looking at the "Surfaces" tab, looking at the "arm" or "torso" surface (since that's what's white) and then seeing if there's an image on the "Base Color" and if the referenced image actually exists. (Missing images also probably show up in your log.)
- Your character has a "geoshell" applied to it (for things like makeup, tattoos, etc.) and the geoshell isn't transparent in the correct areas, or itself has a similar materials issue - missing image or the like.
The other possibility that comes to mind is that you're using a non-iRay rendering engine (e.g. 3Delight or Filament) with a character that only has iRay materials, and Daz Studio isn't succeeding in converting the iRay materials to materials for that renderer. That could happen if the character uses a custom shader.
One work-around might be to apply the materials from a character that works to the character that doesn't. In other words, you'd have the mesh from one character, but the materials from another.
