Hello, john macco.
As practice shows, SD / DVD discs can spoil over time. Not completely, but on many drives are no longer readable (I have a large collection of discs 2000-2010, so there is such experience)...
To begin with, try to clean the laser lens on the drive with a special cleaning disc. Then carefully clean the surface of the "problematic" CD disc. These products are sold in computer stores. If this doesn't work, try contacting a nearby service center and asking them to copy the SD drives to a new one or to a flash drive/SD card/external HDD.