I have made many CD's of copy of books I have written on my mac-mini using words for mac. I now have ElCaptian 10.11.5. I put in a CD to copy a written book and it won't recognize the CD. I have been on line for two days with no results. It won't open the CD. I depended on my computer to record over ten years of work and it won't recognize the CD's. Catastrophic to me? Yes every response I have found refers me to how to burn a CD. I now have to go and find a computer that will open my CD's. It will play music cd's.