protected function create_error_message( $message_name, $value ) {

		$message = $this->get_message_template( $message_name );

		if ( ! is_scalar( $value ) ) {
			$value = $this->get_value_as_string( $value );
		}

		// replacing the placeholder for the %value%
		$message = str_replace( '%value%', $value, $message );

		// replacing the possible options-placeholder on the message
		foreach ( $this->options as $search => $replace ) {
			$replace = $this->get_value_as_string( $replace );
			$message = str_replace( '%' . $search . '%', $replace, $message );
		}

		return $message;
	}