You have probably applied a material file that applies a special texture from a plug-in shader package, such as the Human Surface Shader, or pwSurface2. Make sure you own and have installed the plug-in correctly. If you still have this problem, please try reinstalling the shader plug-in and restarting DAZ Studio. Shader plug-ins like these are a great way to enhance the look of your lighting and artwork, and can work magic for special materials.
Elite Human Surface Shader: http://www.daz3d.com/i/3d-models/-/elite-human-surface?item=7412&_m=d