My internet service provider is "Orange".

Turn off account hub in general settings and try again.

Hello, I keep getting the following message: Unable to connect to the server. The configuration, username, or password is probably incorrect. Attached is an image of the settings so you can check what the account hub corresponds to.

Attached is an image of the settings so you can check what the account hub corresponds to for me... Is this the correct setting I need to change?

Yes, that is what you want unchecked.

Have you tried creating your account with account hub unchecked?

Yes I did ans so I keep getting the following message: Unable to connect to the server. The configuration, username, or password is probably incorrect.

I think that if I switch my account directly from POP to IMAP, I will lose all my messages and folders. Is that right?

Are you using Orange settings for IMAP accounts?

https://www.getmailbird.com/setup/access-orange-fr-via-imap-smtp

You cannot switch an account from one type to another. You must create the IMAP account as a new account.

Are you using a password that must be generated for 3rd-party mail apps, or the account password to log into webmail?

https://assistance.orange.fr/ordinateurs-peripheriques/installer-et-utiliser/l-utilisation-du-mail-et-du-cloud/mail-orange/le-mail-orange-nouvelle-version/parametrer-la-boite-mail/mail-orange-comment-acceder-a-sa-boite-mail-orange-depuis-une-application-ou-un-logiciel-de-messagerie-non-fourni-par-orange_434630-964290#

Are you using Orange settings for IMAP accounts? : Yes

Thank You sfhowes ! It worked! I created a password generated for 3rd-party mail apps on Orange, my 3rd-party mail apps. And it worked right away.

And thank you to Rick for supporting me too, more morally than technically, but it's good to know you're not alone!