Daniel,
thank you for your answers, but I’m afraid that my problem is not yet solved.
There are no differences between the user login and user_nicename of authors returned and those who aren’t.
About users_capabilities, it seems not to be related to my problem. Indeed, I have some admins who are returned, others not. Same for publishers, subscribers, etc…
If I change the capabilities of an author to a publisher, it doesn’t always appear in the list. So I think that my problem doesn’t come from users_capabilities.
I don’t understand why authors aren’t returned :/
My WordPress is configured in French, maybe it’s a lead ?
I’ve a latest question, what is the table of the database where the plugin looks for the authors?
Thank you in advance ??
Emmanuel
EDIT : By verifying in PHPMyAdmin, there is not the term ‘author’ attached to users. Maybe that the problem would come from here ? Is there a way to create this relation ?