Can not open book

Hello,

i bought the following book: Zarbock_Praxisbuch-Verhaltenstherapie_9783899674712

I have downloaded it and accessed it on my macbook and on my iphone. I had to access it with a new ID when opening it on my iphone. Now I wanted to open it on my windows computer and I keep getting this message when wanting to login with my ADOBE ID:

"Digital editions konnte keine Verbindung zum Aktivierungsserver herstellen. Stellen Sie sicher, dass Sie mit dem Internet verbunden sind."

My internet is working fine. How can I get access to the book on this computer?

Best regards,

Lioba