Notice: The Called Constructor Method For WP_Widget Is Deprecated Since Version 4.3.0! Use __construct()

If you run with debug on and have installed WordPress 4.3 RC or the full release, you will see this message if a plugin is active that uses a PHP 4 constructor. This may also pertain to constructors in themes that are including standard (non-Layers) widgets.

To Fix Find the problematic plugin and change

parent::WP_Widget

To

parent::__construct