Dowloading ebooks after new authorization

Suddenly, I couldn't read my purchased books in the ADE library. So I de-authorized and then authorized again my MAC as per the following instructions: https://support.ebooks.com/hc/en-gb/articles/115001588846 and it went well. However, when I tried to dowload again the original purchaed files the message in the ADE library is : 

Error getting License. License Server Communication Problem:

E_LIC_ALREADY_FULFILLED_BY_ANOTHER_USER

Many thanks for indicating a solution !