Tip: I have found that viewports 'forget' to display textures when rendering in GL. After checking all of the usual suspects - see settings described above, if still no textures in the rendered VP, then go into design layer and choose drop down render menu to GL options and you will usually find the show texture button toggled off, just toggle to on, render and return to VP - all is good again. VW VPs seem to forget textures occasionally.