Fixing 2 PHP errors

Hi guys, so I have two errors that gets repeated plenty of times in my php errorlog.

First error:

Array to string conversion in woocommerce/zn-woocommerce-init.php on line 96

Line 96 in zn-woocommerce-init.php:

$output .= '<img src="'. woocommerce_placeholder_img_src() .'" alt="Placeholder" width="' . $placeholder_width . '" height="' . $placeholder_height . '" />';

Second error:

The called constructor method for WP_Widget is deprecated since version 4.3.0! Use

__construct()

instead. in wp-includes/functions.php on line 3619

Line 3585 to 3630 in functions.php:

/**
 * Marks a constructor as deprecated and informs when it has been used.
 *
 * Similar to _deprecated_function(), but with different strings. Used to
 * remove PHP4 style constructors.
 *
 * The current behavior is to trigger a user error if <code>WP_DEBUG</code> is true.
 *
 * This function is to be used in every PHP4 style constructor method that is deprecated.
 *
 * @since 4.3.0
 * @access private
 *
 * @param string $class   The class containing the deprecated constructor.
 * @param string $version The version of WordPress that deprecated the function.
 */
function _deprecated_constructor( $class, $version ) {

	/**
	 * Fires when a deprecated constructor is called.
	 *
	 * @since 4.3.0
	 *
	 * @param string $class   The class containing the deprecated constructor.
	 * @param string $version The version of WordPress that deprecated the function.
	 */
	do_action( 'deprecated_constructor_run', $class, $version );

	/**
	 * Filter whether to trigger an error for deprecated functions.
	 *
	 * <code>WP_DEBUG</code> must be true in addition to the filter evaluating to true.
	 *
	 * @since 4.3.0
	 *
	 * @param bool $trigger Whether to trigger the error for deprecated functions. Default true.
	 */
	if ( WP_DEBUG && apply_filters( 'deprecated_constructor_trigger_error', true ) ) {
		if ( function_exists( '__' ) ) {
			trigger_error( sprintf( __( 'The called constructor method for %1$s is <strong>deprecated</strong> since version %2$s! Use %3$s instead.' ), $class, $version, '<pre>__construct()</pre>' ) );
		} else {
			trigger_error( sprintf( 'The called constructor method for %1$s is <strong>deprecated</strong> since version %2$s! Use %3$s instead.', $class, $version, '<pre>__construct()</pre>' ) );
		}
	}

}

Anyone able to spot what I shall edit in these lines?
I thank you in advance and hopefully these errors will be easy to squash 🙂