Editor is juste a text box

Hi Stéphane,

Thank you for testing CommentBox and for your message.

CommentBox automatically switches to a simple textarea when the user submitting the comment is not allowed to post HTML. This behavior is controlled by Joomla’s Text Filters configuration.

You can check this under:

System → Global Configuration → Text Filters

There, you can define which user groups are allowed to post HTML markup.  
By default, Joomla does not allow non-logged-in users (Public group) to post HTML, which is why CommentBox falls back to a basic textarea instead of the rich editor.

If you allow HTML for the relevant user group, the full editor will be displayed automatically.

If you need help choosing the safest configuration, feel free to let me know.

Best regards,  
Lefteris