Cannot open any book on ADE (for Mac)

[bronwynmayb]

I have purchased a book and tried to open it on ADE. It continually got the error code that it could not open as it did not recognize the registration.  I followed all the advice on these forums and nothing worked (including removing the authorization code and starting over). 

Now I am getting another code:

I am beyond frustrated.  I tried to redownload the book, but it won't let me.  I am not impressed with this program at all. 

[diwillster]

I am having the same issue....please ....can someone give us some suggestions to resolve this? I have contacted Kobo....but no resolution yet