And what issues are you having specifically? You need to explain a lot better nad provide system information and otehr details.
Moving this discussion to the Adobe Digital Editions forum.
What exactly heppens when you try to download an ebook from your library? Do you get any error message? An error screenshot would help.
So let us know the vesion of ADE you are using and along with the operating system. On which device are your trying to download ebook to?