Hi. In my very short XP editing in DS3. As far I know IF you want to attach something in the 3D model it will show blank like there is no material in the model / part / piece. As far I know, you need to edit it in Blender. About the textures. Yes, some times show that error. I edited some textures in DS3. When show up that error. I close the game and open it again and "extract" the textures again. Regards!