I had this working before (possibly as a result of installing K-Studio Demo or Netfabb Basic?) so I know it can be done! Something unknown has changed/broken, and I no longer have thumbnail previews of STL files when opening/importing, or in any windows explorer window. Anyone have a fix for this? Extensive Goggling no good so far…
Fixed by reinstalling Kevvox K-studio. Now have glorius grey thumbnails for all stl files again 
Hello
the preview does not appear to me
already rebooted the system (Windows)
Any idea?