cannot transfer Book

After many years of using my Overdrive A/C for getting books from Library got new computer. Have battled with assistance from "Overdrive Help." Unauthorised/Reauthorised  ADE. Kobo detected and Is a  supported device. Cannot transfer books to it. Kobo appears in ADE. dragging books to it results in ERROR MESSAGE     "CE_COPY_NOT_ALLOWED". Am at a loss and do not know what to do. HELP, Ray franklin