Hello Stephane,
Thank you for reaching out and I am happy to assist you with this.
Remove the license key from W3 Total Cache installation from https://hammampacha.com/shop Performance>General settings, Licensing sub-box, license field, and save all settings. Re-enter the license in https://hammampacha.com , verify the license with the “verify license button” and save all settings.
W3 Total Cache Pro should be active after these steps!
Thanks!