I am going to answer my own question.
1- As to why the disk was blank, I do not know.
2- But searching in the Internet I found a product that allowed me to “see” and "copy’ the data in the disk. It was like magic to me, because it happened very easily and immediately.
3- The name of the product is IsoBuster, they even let you “see” your data before you have to pay for it and is very reasonable.
Hope this will help somebody else with the same problem.