Preferential Lite Fix for left sidebar (drop this file in your child theme)

page.php

<?php
/**
 * The template for displaying all pages.
 *
 * This is the template that displays all pages by default.
 * Please note that this is the WordPress construct of pages
 * and that other 'pages' on your WordPress site will use a
 * different template.
 *
 * @package Preferential
 */

$nbSidebars = is_active_sidebar( 'pageleft' ) + is_active_sidebar( 'pageright' ); 
$col_middle = 'col-md-' . (12 - 3*$nbSidebars);

get_header(); ?>

<div id="pref-main-section">
	<div role="main">
    
    <?php get_sidebar( 'top' ); ?>
    
        
        <div class="container">     
            <div class="row">
              <?php if (is_active_sidebar( 'pageleft' )): ?>
              <div class="col-md-3">
                <?php get_sidebar( 'left' ); ?>
              </div>
              <?php endif; ?>
            
            
            	<div class="<?php echo $col_middle; ?>">
                
                    <?php while ( have_posts() ) : the_post(); ?>           
                        <?php get_template_part( 'content', 'page' ); ?>           
                    <?php
                            // If comments are open or we have at least one comment, load up the comment template
                            if ( comments_open() || '0' != get_comments_number() ) :
                                comments_template();
                            endif;
                        ?>           
                    <?php endwhile; // end of the loop. ?>
                    
              </div>
              
              <?php if (is_active_sidebar( 'pageright' )): ?>
              <div class="col-md-3">
                <?php get_sidebar( 'right' ); ?>
              </div>
              <?php endif; ?>
              
            </div>      
        </div>
        
           <?php get_sidebar( 'bottombanner' ); ?>
    </div>
</div>


<?php get_footer(); ?>