I don’t know why, but with this code changed, it works great:
get_header(); ?>
<div id="primary" class="col-md-8 <?php echo esc_attr( of_get_option('blog_sidebar_pos') ) ?>">
<div id="content" class="site-content" role="main">
<?php while ( have_posts() ) : the_post(); ?>
<?php
$hide_th = 0;
global $multipage, $numpages, $page;
if ($multipage && (1 < $page) ) {
$hide_th = 1;
}
if ( has_post_thumbnail() && ( 1 != $hide_th ) ) { ?>
<?php if ( ( '' == of_get_option('single_image_size') ) || ('normal' == of_get_option('single_image_size')) ) { ?>
<figure class="featured-thumbnail thumbnail"><?php the_post_thumbnail(); ?></figure>
<?php } ?>
<?php } ?>
<div class="page_wrap">
<h1 class="entry-title"><?php the_title(); ?></h1>
<?php the_content(); ?>
</div>
<?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();
?>
<?php endwhile; // end of the loop. ?>
</div><!-- #content -->
</div><!-- #primary -->
<?php get_sidebar(); ?>
<?php get_footer(); ?>