If these are purchase books with DRM, you will needt to contact the seller.
If not, then the ePub is including fonts in a newer format that ADE 1.7 doesn't support, and you'll need to use ADE 1.8 (currently in public beta on labs.adobe.com )
I am German and have unfortunately understand their difficulties answer. If I understand it correctly, it's the font, and I was on the side: labs.adobe.com ADE to 1.8 but I can not find anything that helps me further. Can you help me please.
What should I do if I could load it yet.
Thank you for your effort
Translation of my earlier message with some additional info:
(Entschuldigen - Ich habe Deutch auf Gynasium gerlernt - zu fielen jarhen her)
Wenn Sie das buch gekauft mit DRM, an den verkäufer zu sprechen um hilfe.
Wenn nicht, ADE 1.7 verstehe nicht der [encoding - codiertung?] der [Font - ?Schrifft ], aber ADE 1.8 solte. Sie solten ADE 1.8 versuchen von labs.adobe.com ( http://labs.adobe.com/technologies/digitaleditions1-8/ )
Warnung - ADE 1.8 is nur in Englisch ( ADE in labs.adobe.com is currently only available in English).
many thanks for your help, now I have understood it is an update. Your help was very very nice.
Until next time