text: advanced rendering for AutoCAD
  I'm not been able to bring ceiling materials from Ceiling/Acoustical Tile file into Materials
  dialog box to apply to layers in AutoCAD. I checked the rest of the files and they all worked.
  Any idea on how to fix this issue? Thank you kindly.
  Thank you kindly for your files.
  They worked fine and just in time for my deadline.
  I appreciate it.
  I believe you are experiencing what I had awhile back - it has to do with how the material files are physically named (specifically the ceiling tiles, I don't recall coming across any other material not working). You just need to physically rename the actual material files and remove the commas from the name.