第一个插件以某种方式破坏了第二个插件（第二个插件的内容根本没有显示）：

plugins/featured-images.php:

<?php
/* Plugin Name: Featured Jobs
Plugin URI: [Enter your website URL]
Description: [Enter brief description of plugin]
Version: [Enter version number of plugin (probably 1.0)]
Author: [Enter your name]
Author URI: [Enter your website URL]
*/
class Featured_Jobs extends WP_Widget {

    /**
     * Register widget with WordPress.
     */
    public function __construct() {
        parent::__construct(
            \'featured_jobs\', // Base ID
            \'Featured Jobs\', // Name
            array( \'description\' => __( \'A Foo Widget\', \'text_domain\' ), ) // Args
        );
    }

    /**
     * Front-end display of widget.
     *
     * @see WP_Widget::widget()
     *
     * @param array $args     Widget arguments.
     * @param array $instance Saved values from database.
     */
    public function widget( $args, $instance ) {
        extract( $args );
        $title = apply_filters( \'widget_title\', $instance[\'title\'] );

        echo $before_widget;
        if ( ! empty( $title ) )
            echo $before_title . $title . $after_title;
    ?>
      <ul class="featured-jobs">
      <?php // Create and run custom loop
        $custom_posts = new WP_Query();
        $custom_posts->query(\'post_type=jobs&posts_per_page=8\');
        while ($custom_posts->have_posts()) : $custom_posts->the_post();
      ?>
        <li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li>
      <?php endwhile; ?>
      <li class="see-all-positions"><a href="http://www.pixelmatic.com/open-jobs/">See All Positions >></a></li>
      </ul>

    <?php

        echo $after_widget;
    }

    /**
     * Sanitize widget form values as they are saved.
     *
     * @see WP_Widget::update()
     *
     * @param array $new_instance Values just sent to be saved.
     * @param array $old_instance Previously saved values from database.
     *
     * @return array Updated safe values to be saved.
     */
    public function update( $new_instance, $old_instance ) {
        $instance = array();
        $instance[\'title\'] = strip_tags( $new_instance[\'title\'] );

        return $instance;
    }

    /**
     * Back-end widget form.
     *
     * @see WP_Widget::form()
     *
     * @param array $instance Previously saved values from database.
     */
    public function form( $instance ) {
        if ( isset( $instance[ \'title\' ] ) ) {
            $title = $instance[ \'title\' ];
        }
        else {
            $title = __( \'New title\', \'text_domain\' );
        }
        ?>
        <p>
        <label for="<?php echo $this->get_field_id( \'title\' ); ?>"><?php _e( \'Title:\' ); ?></label> 
        <input class="widefat" id="<?php echo $this->get_field_id( \'title\' ); ?>" name="<?php echo $this->get_field_name( \'title\' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>" />
        </p>
        <?php 
    }

} // class Foo_Widget

// register Foo_Widget widget
add_action( \'widgets_init\', create_function( \'\', \'register_widget( "featured_jobs" );\' ) );

plugins/theme/theme.php:

add_action( \'widgets_init\', create_function( \'\', \'register_widget(   "px_reviews_widget" );\' ) );


class Px_Reviews_Widget extends WP_Widget {

    /**
     * Register widget with WordPress.
     */
    public function __construct() {
        parent::__construct(
            \'px_reviews_widget\', // Base ID
            \'Game - Reviews\', // Name
            array( \'description\' => __( \'Game - Reviews\', \'text_domain\' ), ) // Args
        );
    }

    /**
     * Front-end display of widget.
     *
     * @see WP_Widget::widget()
     *
     * @param array $args     Widget arguments.
     * @param array $instance Saved values from database.
     */
    public function widget( $args, $instance ) {

        if ( !is_singular(\'games\')) { 
            return;
        }

        extract( $args );
        $title = \'Reviews\';//apply_filters( \'widget_title\', $instance[\'title\'] );

        echo $before_widget;
        if ( ! empty( $title ) )
            echo $before_title . $title . $after_title;
        //echo __( \'Hello, World!\', \'text_domain\' );


    $templates = array();

        $templates[] = "game-reviews.php";


    // Backward compat code will be removed in a future release
    locate_template($templates, true);      

        echo $after_widget;
    }

    /**
     * Sanitize widget form values as they are saved.
     *
     * @see WP_Widget::update()
     *
     * @param array $new_instance Values just sent to be saved.
     * @param array $old_instance Previously saved values from database.
     *
     * @return array Updated safe values to be saved.
     */
    public function update( $new_instance, $old_instance ) {
        $instance = array();
        $instance[\'title\'] = strip_tags( $new_instance[\'title\'] );

        return $instance;
    }

    /**
     * Back-end widget form.
     *
     * @see WP_Widget::form()
     *
     * @param array $instance Previously saved values from database.
     */
    public function form( $instance ) {
        /*
        if ( isset( $instance[ \'title\' ] ) ) {
            $title = $instance[ \'title\' ];
        }
        else {
            $title = __( \'New title\', \'text_domain\' );
        }
        */
        ?>
        This widget only show on Game single page
        <?php 
        /*
        ?>
        <p>
        <label for="<?php echo $this->get_field_id( \'title\' ); ?>"><?php _e( \'Title:\' ); ?></label> 
        <input class="widefat" id="<?php echo $this->get_field_id( \'title\' ); ?>" name="<?php echo $this->get_field_name( \'title\' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>" />
        </p>
        <?php 
        */
    }

}