Thanks for you rreply.
Yes, the casm si not the book. It is an xml file and contains the encoded book url and drm informations I suppose.
I tried to download it directly but it can't be read on the edge : There was an error opening the document.

So maybe somebody from edge can help because E_ADEPT_ACSM_NO_FULLFILLMENT_TOKEN must be an edge specific error message and as we don't have (as I know ?) any source, and don't have access to log, I'm unable to diagnose anything ...

Mike