Issues opening acsm files over ADE on my macbook

Hi,

i bought e-books over an official german retailer (Thalia) and they are in an ACSM file format. When i try to add them to ADE (version 4.5) on my macbook this errormessage pops up:

Fehler beim Abrufen der Lizenz. Lizenzserver-Kommunikationsfehler:
E_AUTH_BAD_DEVICE_KEY_OR_PKCS12