E_ADEPT_DOCUMENT_TYPE_UNKNOWN error from ADE or other readers

A user may see this error when trying to download an ebook to Adobe Digital Editions (ADE) or possibly other readers where the ebooks are hosted by Adobe Content Server.

This error is a little misleading. The error is usually not directly related to the document type per se. In most cases, it is caused by the fact that the encrypted book file can't be accessed or, more generally, that the ACS media folder is inaccessible on the ebook server side. In versions of ADE older than 2.0, similar errors may show as an I/O error and list the URL of the book in question.

To narrow down the problem, try accessing the book through a browser. If you know the URL where the book should exist, try to download the book using that address. Note that even though the book should be accessible through any browser, it is encrypted and cannot be read.

If you can't figure out where the book is, try using the thumbnail link if you see one in the ACSM file. The link should look like this:

http://acs-server.com:8080/media/02a9759f-18ef-4baa-afcc-71e36d018e02.jpg

ADE will try to download the book from this location. If you can see the image in a browser, replace the file extension (jpg in this example) with the book's extension (pdf or epub) and see if you can reach the book that way.

If either of these checks fail, you will need to look through your media folder:

1. Does the media server (folder) exist?
2. Is the URL and location you have in your packaging configuration file correct?
3. Is there a case mismatch in the name of the directory on the server compared with the name in the fulfillment server config file on ACS server?
4. Does the user account used by Tomcat services have the appropriate read/access permissions for this directory?
5. Make sure everything is in order, restart Tomcat, and perform the above checks again.

If you're still experiencing problems, please feel free to open a case in the customer portal, or contact Datalogics supp