This error comes when you previously downloaded the book with some authorization credentials in ADE.
Now again if you try to download the book from same download link but current ADE authorization is different, you will receive this error.
1. Make sure ADE is authorized with same credentials, as it was authorized when book was downloaded for the first time.
Then this error will not come.
How would I do that? The book was downloaded some time ago and I do not understand why there would be different credentials when I only have one account with ADE. Unless my Sony account created a different account with ADE that I am not aware of.
I have the same problem here.
Two days ago I bought a book and tried to open it on my new device, without remembering I did not yet activated it.
When requested I activated it but now I receive an error message that says the book belongs to another user.
Also I have to say I have a lot of problems because there is not a linux version of ADE