After upgrading to Adobe Digital Editions 1.5 or later, you are unable to open some or all of your eBooks and you receive the following error:
This issue appears to be caused by a failure in the process of moving your books from anonymous activation to Named activation. This happens during the migration process that occurs when you first install Digital Editions 1.5 or later. Adobe Support will continue to investigate this issue.
Disclaimer: The following solution involves the Windows System Registry. Editing or manipulating the registry incorrectly can result in serious system damage, which may require reinstallation of the operating system. If you are not comfortable editing the registry then it's best to take your machine to a professional. If you choose to proceed it is essential to create a complete system backup and a Windows System Restore Point before proceeding. Adobe Systems cannot be held responsible for damage resulting from this information.
If the above troubleshooting does not allow you to recover your books, please open a Technical Support web case at http://www.adobe.com/support/digitaleditions.
We are asking customers to provide the following information to help us determine the cause of this issue. The more of this information you can provide (especially about your ebook activations) the better Adobe Support can assist you:
Attach the error log files to the case. There are two files, both in the My Digital Editions folder. (On Windows XP: C:\Documents and Settings\<username>\My Documents\My Digital Editions).
For more details see http://www.adobe.com/products/digitaleditions/help/.
In addition, please copy and paste these questions into your webcase, and provide as much information as possible.