Broken dashboard after adding project

Hello, I am building a personal portfolio site.

My admin section was working fine and I was adding in a few projects and giving them feature images. Then for some reason when I went to add another one it just suddenly broke. I hadn’t changed any php only css. I have undone some of the last lines on code I type in the index page but it was not the problem.

This is the error message i am getting:

Warning: Cannot modify header information – headers already sent by (output started at /Applications/XAMPP/xamppfiles/htdocs/portfolio/wp-content/themes/edwardgyngell/posttypes.php:39) in /Applications/XAMPP/xamppfiles/htdocs/portfolio/wp-includes/pluggable.php on line 881

Can any help me please?

This is my index page:

<?php get_header(); ?>
<div class="container">
	<div id="contentwrap">
        <div id="masonry-index">
				<?php

                global $query_string;
                query_posts($query_string . "post_type=projects&post_status=publish&posts_per_page=50");
                if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>

                <div class="project">
                    <a href="<?php the_permalink(); ?>" title="<?php the_title(); ?>">
                        <?php the_post_thumbnail(); ?>
                        <h2><?php the_title(); ?></h2>
                    </a>
                </div>

                <?php endwhile;
                endif; ?>

        </div> <!-- End of content -->
	</div><!-- End of container -->
</div> <!-- End of profile -->
<?php get_footer(); ?>
This is my posttypes.php

// Add new post type for Projects

add_action ('init', 'projects_init');
function projects_init()
{
		$project_labels = array(
			'name' => _x('Projects', 'post type genral name'),
			'singular_name' => _x('Project', 'post type singular name'),
			'all_items' => __('All Projects'),
			'add_new' => _x('Add new project', 'projects'),
			'add_new_item' => __('Add new project'),
			'edit_item' => __('Edit project'),
			'new_item' => __('New project'),
			'view_item' => __('View project'),
			'search_item' => __('Search in projects'),
			'not_found' => __('No projects found'),
			'not_found_in_trash' => __('No projects found in trash'),
			'parent_item_colon' => ''
		);

		$args = array(
			'labels' => $project_labels,
			'public' => true,
			'publicly_queryable' => true,
			'show_ui' => true,
			'query_var' => true,
			'rewrite' => true,
			'capability_type' => 'post',
			'hierarchical' => false,
			'menu_position' => 5,
			'supports' => array('title', 'editor','thumbnail', 'excerpt', 'custom-fields')
		);
		register_post_type('projects',$args);