Try these troubleshooting steps if you see a Content Locked error in Adobe Digital Editions (ADE) while using your PC or Mac.

If you receive a Content Locked error when reading books on ADE, the eBook  you’re trying to read is protected by Digital Rights Management (DRM). DRM prevents the unauthorized copying or redistribution of eBooks to protect the rights of authors and publishers.

Most public library eBooks are protected with DRM.

1. Open Adobe Digital Editions.
2. Delete the file from Adobe Digital Editions as well as from My Digital Edition (under My Documents)
   

3. Make sure that the date and time on your eReader is correct.

4. De-authorize your computer:
   

   a. Press CTRL+SHIFT+D all at the same time. (If you're on a Mac, press Command+Shift+D).

   b. Enter your Adobe Digital Editions password.

   c. Click Continue.

   d. Click Erase Authorization.

5. De-authorize your eReader:

6. a. Plug in your Kobo eReader.

   b. Tap Connect on your eReader

   c. Right-click on Kobo eReader on the left under Devices.

   d. Click Erase Device Authorization.

   e. Click Erase Authorization.

   6. Close Adobe Digital Editions.

7. Unplug your eReader.

8.  Authorize your eReader and computer:

   a. Plug in your eReader.

   b. Launch Adobe Digital Editions.

   c. Authorize your device with your Adobe ID login.

   9. Re-download the file and transfer it to your eReader.