My kobo gave me a message that the DRM was unauthorized. How do I fix it?

This 'fix' no longer works as the authorisation says for the computer, not the device now.  Somewhere else it said that the authorisation transfers when the book is downloaded to my Kobo.  It doesn't.   Does anyone know of an up to date fix please.

Are you using Digital Editions to transfer books to your Kobo eReader? I so you must authorize your eReader with Adobe.

When you authorize your Kobo eReader, Adobe adds it to the list of devices associated with your Adobe account.

Adobe limits the number of eReaders and computers you can use with their software, which is why this is necessary.

To authorize your eReader:

1. Connect your Kobo eReader to your computer and select Manage Library.
2. Start Digital Editions.
   If you were already using Digital Editions, restart it so that it will find your eReader and start the Device Setup Assistant.
3. Click Authorize Device.
4. Click Finished to complete the process.