[@houd Participant 2 years, 3 months ago]

You need to pick the allowed html tags that the users can use in your “functions.php”, like so:

function wp_bbpress_allow_tags(){
    return array(
        'span'=> array(
            'class'     => true,
            'style'     => true,
        ),
	// add other tags to allow here
    );
}
add_filter('bbp_kses_allowed_tags', 'wp_bbpress_allow_tags');

Keep in mind the tags you pick here are the only tags that will be allowed, so list all of them here.