Erase Authorisaion failure

From office@davidengland.co.uk

Today I purchased an ebook from Rakuten Kobo and downloaded it, URLLink.acsm. When I sought to transfer it to my Adobe library I got a message Error! Check Activation. Rakuten Kobo advised as below. When I tried to Erase Authorization, I got a message, Unable to Erase Authorization Please, try after some time, which I did repeatedly with the same result. Please, advise me how to access the ebook from Rakuten Kobo.

Rakuten Kobo's advise:

If you're encountering an "Error! Check Activation" message when trying to open a URLLink.acsm file in Adobe Digital Editions on your Windows 10 PC, it suggests there's an issue with the authorization of Adobe Digital Editions. To resolve this, you should de-authorize and then re-authorize your computer with Adobe Digital Editions. Here are the steps you can follow:

1. Open Adobe Digital Editions on your PC.
2. Go to the "Help" menu and choose "Erase Authorization".
3. De-authorize Adobe Digital Editions.
4. Once de-authorized, go back to the "Help" menu.
5. Choose "Authorize Computer" and enter your Adobe ID and password.
6. Click "Authorize" to re-authorize your computer.