unable to sync new book into e-reader

[#1]

I'd already de- & then re-authorize Adobe Digital Editions countless times. When attempting to sync library book(s), it sometimes says "reader for PC has stopped working" or syncing goes on long time but when open e-reader, new book(s) not downloaded or imported.  What am I missing ?!  HELP PLEASE !

[#2]

I'd already de- & then re-authorize Adobe Digital Editions countless times. When attempting to sync library book(s), it sometimes says "reader for PC has stopped working" or syncing goes on long time but when open e-reader, new book(s) not downloaded or imported.  What am I missing ?!  HELP PLEASE !