copperpen, on 22 June 2015 - 12:18 PM, said:
Nothing to do with steam engine physics. It is a warning that was put in to show up "defective" shape files, but can be turned off in Options/Experimental. Look for Show Shape warnings and un-tick the box.
Actually it's not even about "defective" shape files... it's telling you the shape file has some faces that are not textured. The same facts are reported in another message, a warning that includes the word "Diffuse".
IMO the vertex code check and message should be removed and the "Diffuse" message could be made more informative by saying "Untextured faces detected".