Adobe Digital Editions asks me to authorize my PC (Windows 7). Trying to do so I get the following message: "Error activating server. Code:E_AUTH_NOT_READY. Digital Editionserror at the activating server". What does that mean? What should I do?

Adobe Digital Editions asks me to authorize my PC (Windows 7). Otherwise I can't transfer ebooks from the PC to me E-reader. Trying to do so I get the following message (in Dutch): "Fout activeringsserver. Code:E_AUTH_NOT_READY. Digital Editions heeft een fout gedetecteerd op de activeringsserver". In English: "Error activating server. Code:E_AUTH_NOT_READY. Digital Editions has detected an error at the activating server". What does that mean? What should I do?