Adobe could transfer books to Kobo on old HP laptop but on new Mac I get this error message: CE_COPY_NOT_ALLOWED - No permission to copy book.

I have the same version of Adobe Digital Editions, the only difference is for Mac or PC. This afternoon I signed out epub books from my local library and could transfer them from Adobe Digital editions on my dying dinosaur laptop, but when I tried to do it from my new Mac, I got the error message. My Kobo is authorized on both machines. What do I do?