Content not showing up when using custom template + sidebar

the problem is you never call the content!!!

change your dashboard.php to something like this

<?php
/*
Template Name: User Dashboard
*/
?>


<?php get_header(); ?>

 <?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
            <div id="content" role="main">

            <?php  the_content(); ?>

            </div><!-- #content -->

<?php endwhile; else: ?>
    <p><?php _e('Sorry, no posts matched your criteria.'); ?></p>
<?php endif; ?>


<?php get_sidebar( 'dashboard' );?>
<?php get_footer(); ?>