Registration and login workflow

There is a problem in the registration workflow:
After sending the registration form I get the message as on the capture in the appendix and the login is not done.
In the backend (user management) everything is ok and the username is correctly registered.
By returning to the frontend homepage and logging in, the username is recognized.
Any idea to avoid this?

The message isn't in English so I've no idea what error you're seeing. Please switch the site to English and retry then provide the full error message as this will allow me to find where the message is coming from exactly. Your registration form having no inputs is strange though. Are you using CB Conditional to condition fields? Is CB Core in CB > Plugin Management public and published?

Hello,
the message displays "Please enter your name" (see attachment)
cb core published and public
autologin system autoaction activated
no conditional
and in user management :
user registered as desired with
banned : no
activated : yes
confirmed : yes
approuved : yes
acl usergroup : registered

It looks like it's doing that because there's no fields available to the user. Make sure you've fields available to registration within CB > Field Management and that the tab they're on is published. By default CB works out of the box so you've changed something in regards to the core registration fields or their tab. Core fields (username, name, password, email, etc..) are placed on the Contact Info tab by default.