Parse error

Remove <?php on line 17.

Thanks, but it does not work…

In what way doesn’t it work? It’s plainly incorrect.

I remove <?php on line 17 but it does not work…

<?php get_header(); ?>

<div id="content">

	<div id="contentleft">

		<div class="postarea3">

		<?php include(TEMPLATEPATH."/breadcrumb.php");?>
			<?php echo category_description( $category_id ); ?>

if (have_posts()) {
  while (have_posts()) {
    the_post();
  }

                $cats = get_categories();
                foreach ($cats as $cat) {

                query_posts('showposts=10&cat=718-CATEGORIE'.$cat->cat_ID);

            ?>

			 <div class="article4">

			<?php the_excerpt(); ?>
			</div>

		 <?php endwhile; else: ?> 

			<p><?php _e('Sorry, no posts matched your criteria.'); ?></p><?php endif; ?>
			<p><?php if(function_exists('wp_simple_pagination')) {
    wp_simple_pagination();
} ?></p>

		</div>

	</div>

<?php include(TEMPLATEPATH."/sidebar.php");?>

</div>

<!-- The main column ends  -->

<?php get_footer(); ?>

But what error message are you getting now?

My error:
Parse error: syntax error, unexpected T_ENDWHILE in /web/doclibre/www/wp-content/themes/lifestyle_20/category.php on line 36

How can you be getting an error on the same line if you removed the line I suggested?

I dont now .. I just remove <?php on line 17 and the error remains the same..

Are you trying to use two loops in this template file? If so, you shouldn’t be using query_posts() for the second loop but should use get_posts() or WP_Query() instead.

there is a <?php missing before if (have_posts()) { in line 12;

but the whole code does not make any sense;
the loop is not started properly, the query is not followed by a loop etc.

can you describe what you are trying to do with the code?

https://codex.www.ads-software.com/The_Loop

I want to display a specific category (category id=718)…

category.php should be left alone/unedited to show all possible categories (which it will do automatically);

if you want to show one category with a special layout, consider to create a category template; https://codex.www.ads-software.com/Category_Templates

if you want that a page should show posts of a category, create a page template; https://codex.www.ads-software.com/Pages#Creating_Your_Own_Page_Templates
for which you could start with a copy of index.php, add the necessary code at the top, and add a query before the loop;
example based on your posted code: https://pastebin.com/MfyCMfgV

(more-or-less a guess, as I am still not sure what you are trying to achieve)

related Codex chapters:
https://codex.www.ads-software.com/Theme_Development
https://codex.www.ads-software.com/The_Loop
https://codex.www.ads-software.com/Function_Reference/query_posts

where do you want to show that particular category?

You understand ;), I want to show one category with a special layout.
I am French and I have difficulties in translating the codex. Thanks for the links, I’ll look at it.

Success:

<?php get_header(); ?>

<div id="content">

	<div id="contentleft">

		<div class="postarea3">

		<?php include(TEMPLATEPATH."/breadcrumb.php");?>
			<?php echo category_description( $category_id ); ?>

		<?php if (have_posts()) : ?>

<?php while (have_posts()) : the_post(); ?>

			 <?php get_the_category_by_ID( 718 ); ?> 

			 <div class="article4">

			<?php the_excerpt(); ?>
			</div>

			 <?php endwhile; else: ?>

			<p><?php _e('Sorry, no posts matched your criteria.'); ?></p><?php endif; ?>
			<p><?php if(function_exists('wp_simple_pagination')) {
    wp_simple_pagination();
} ?></p>

		</div>

	</div>

<?php include(TEMPLATEPATH."/sidebar.php");?>

</div>

<!-- The main column ends  -->

<?php get_footer(); ?>

Thank you very much ^^