the_excerpt();

hi ;
when i use the_excerpt();
i will disappear sidebar ,
Why??!!
please HELP ME

index.php

<?php
/**
 * The main template file.
 *
 * This is the most generic template file in a WordPress theme
 * and one of the two required files for a theme (the other being style.css).
 * It is used to display a page when nothing more specific matches a query.
 * E.g., it puts together the home page when no home.php file exists.
 * Learn more: http://codex.ww.wp.xz.cn/Template_Hierarchy
 *
 * @package pir-Javid
 */

get_header(); ?>

	<section class="feature-image feature-image-default-alt" data-type="background" data-speed="2">
		<h1 class="page-title">Blog</h1>
	</section>

<!--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=BLOG CONTENT=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-->
	<div class="container">
		<div id="primary" class="row">
			<main id="content" class="col-sm-8" role="main">
				<?php if ( have_posts() ) : ?>

					<?php if ( is_home() && ! is_front_page() ) : ?>
						<header>
							<h1 class="page-title screen-reader-text"><?php single_post_title(); ?></h1>
						</header>
					<?php endif; ?>

					<?php /* Start the Loop */ ?>
					<?php while ( have_posts() ) : the_post(); ?>

						<?php

						/*
                         * Include the Post-Format-specific template for the content.
                         * If you want to override this in a child theme, then include a file
                         * called content-___.php (where ___ is the Post Format name) and that will be used instead.
                         */
						get_template_part( 'template-parts/content', get_post_format() );
						?>

					<?php endwhile; ?>

					<?php the_posts_navigation(); ?>

				<?php else : ?>

<!--					--><?php //get_template_part( 'template-parts/content', 'none' ); ?>

<!--					--><?php //get_template_part( 'content', get_post_format() ); ?>

				<?php endif; ?>
			</main>	<!-- content -->
			<!--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=SIDEBAR=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-->
			<aside class="col-sm-4 widgetleft">
				<?php get_sidebar(); ?>
			</aside><!-- col -->
			</div><!-- primary -->
		</div><!-- container -->

<?php get_footer(); ?>

content.php

<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
	<header class="entry-header">
		<?php the_title( sprintf( '<h3 class="entry-title"><a href="" rel="bookmark">', esc_url( get_permalink() ) ), '</a></h3>' ); ?>

		<?php if ( 'post' == get_post_type() ) : ?>
			<div class="post-details">
				<i class="fa fa-user"></i> <?php the_author(); ?>
				<i class="fa fa-clock-o"></i> <time><?php the_date(); ?></time>
				<i class="fa fa-folder-open"></i> <?php the_category(', '); ?>
				<i class="fa fa-tags"></i><?php the_tags('', ', ', ''); ?>
				<?php pir_javid_posted_on(); ?>
				<div class="post-comments-badge">
					<a href=""><i class="fa fa-comments"></i><?php comments_number(0,1,'%');?></a>
				</div><!-- post-comments-badge -->
				<div><?php edit_post_link( ' edit','<div><i class="fa fa-pencil"></i>','</div>' ); ?></div>
			</div><!-- post-details -->
		<?php endif; ?>
	</header><!-- .entry-header -->
	<div class="post-image">
		<?php if ( has_post_thumbnail() ) { ?>
		<?php the_post_thumbnail();?>
		<?php  } ?>
	</div> <!-- Post-Image -->

	<div class="post-excert">
		<?php

			the_excerpt();
		?>

	</div><!-- post-excpert -->
</article><!-- #post-## -->

this my problem :

<div class="post-excert">
		<?php

			the_excerpt();
		?>

	</div><!-- post-excpert -->

if i hide this , my problem solve!!!