Deprecated

Other error message:

WPCF7_TagGenerator::add(): Use of tag generator instances older than version 2 is deprecated. Version 1 instance (CAPTCHA) detected.

which could be fixed in /wp-content/plugins/captcha-for-contact-form-7/compatibility/cf7/Backend.class.php, line 263, with:

/**
 * Add the captcha button to the contact form 7 generator
 */
private function addCaptchaToCF7() {
    if ( class_exists( '\WPCF7_TagGenerator' ) ) {
        $tag_generator = \WPCF7_TagGenerator::get_instance();
        $tag_generator->add( 'f12_captcha', __( 'Captcha', 'captcha-for-contact-form-7' ), 'captchaCallback', array( 'version' => '2' ) );
    }
}