This error message is received when there is an issue with the authorisation of your Adobe Digital Editions software.

To fix the issue you need to first deauthorise Adobe Digital Editions and then authorise it again.

Please follow the steps on this help page to deauthorise Adobe Digital Editions.

Please follow the steps on this help page to authorise Adobe Digital Editions again.

Once you have followed the above steps, if the ebook still will not open, please try deleting the ebook and downloading it again using a new acsm file downloaded from your eBooks.com account.

If you are still having difficulty deauthorising please contact our support team.