How do I drag and drop from ADE to Kobo ereader without having the message "copy not allowed"?

Both my computer and kobo e reader are authorized.  I read a troubleshooting message that said I could deauthorize and try to drag and drop, but this didn't work.  I have been reading everything I can find on how to fix this problem.  I also read a message that Kobo ereaders don't work with ADE 4.0 at this time.  So I uninstalled and downloaded version 3.0.  I still can't fix my problem.  Can someone please help me????