Error

I downloaded a book from the library in EPUB format.  I opened Adobe Digital Editions and it is there.  The application also 'found' my Sony e-reader PRS350.

When I try to drag the book and drop onto the e-reader, I get an error....  CE_COPY_NOT_ALLOWED - no permission to copy the book.

This is my first time using this application.  Any ideas why this is happening?

Thanks