Hi Lisa

You can also let them search, but show them nothing (or a custom message) using this type of PHP code (change the number 1234 for the ID number of your search form and change the line echo '<div>Nothing to see here folks!</div>'; for whatever you want before the filter is used instead of the results – or remove for nothing at all):

global $searchandfilter;
$sf_current_query = $searchandfilter->get(1234)->current_query();
if ((!$sf_current_query->is_filtered())&&($sf_current_query->get_search_term()=="")) {
  echo '<div>Nothing to see here folks!</div>'; 
} else {
  // your theme template code here for the part that runs the loop, e.g. if ( $query->have_posts() ) .....
}

For example, if you were using the shortcode method. OK, if you have followed the documentation to make a copy of the results.php into a new folder called search-filter in your child theme or theme folder, then replace the contents of that template file with this:

<?php
/**
 * Search & Filter Pro 
 *
 * Sample Results Template
 * 
 * @package   Search_Filter
 * @author    Ross Morsali
 * @link      http://www.designsandcode.com/
 * @copyright 2015 Designs & Code
 * 
 * Note: these templates are not full page templates, rather 
 * just an encaspulation of the your results loop which should
 * be inserted in to other pages by using a shortcode - think 
 * of it as a template part
 * 
 * This template is an absolute base example showing you what
 * you can do, for more customisation see the WordPress docs 
 * and using template tags - 
 * 
 * http://codex.wordpress.org/Template_Tags
 *
 */

global $searchandfilter;
$sf_current_query = $searchandfilter->get(1234)->current_query();
if ((!$sf_current_query->is_filtered())&&($sf_current_query->get_search_term()=="")) {
  echo '<div>Nothing to see here folks!</div>'; 
} else {
	
	if ( $query->have_posts() )
{
	?>
	
	Found <?php echo $query->found_posts; ?> Results<br />
	Page <?php echo $query->query['paged']; ?> of <?php echo $query->max_num_pages; ?><br />
	
	<div class="pagination">
		
		<div class="nav-previous"><?php next_posts_link( 'Older posts', $query->max_num_pages ); ?></div>
		<div class="nav-next"><?php previous_posts_link( 'Newer posts' ); ?></div>
		<?php
			/* example code for using the wp_pagenavi plugin */
			if (function_exists('wp_pagenavi'))
			{
				echo "<br />";
				wp_pagenavi( array( 'query' => $query ) );
			}
		?>
	</div>
	
	<?php
	while ($query->have_posts())
	{
		$query->the_post();
		
		?>
		<div>
			<h2><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h2>
			
			<p><br /><?php the_excerpt(); ?></p>
			<?php 
				if ( has_post_thumbnail() ) {
					echo '<p>';
					the_post_thumbnail("small");
					echo '</p>';
				}
			?>
			<p><?php the_category(); ?></p>
			<p><?php the_tags(); ?></p>
			<p><small><?php the_date(); ?></small></p>
			
		</div>
		
		<hr />
		<?php
	}
	?>
	Page <?php echo $query->query['paged']; ?> of <?php echo $query->max_num_pages; ?><br />
	
	<div class="pagination">
		
		<div class="nav-previous"><?php next_posts_link( 'Older posts', $query->max_num_pages ); ?></div>
		<div class="nav-next"><?php previous_posts_link( 'Newer posts' ); ?></div>
		<?php
			/* example code for using the wp_pagenavi plugin */
			if (function_exists('wp_pagenavi'))
			{
				echo "<br />";
				wp_pagenavi( array( 'query' => $query ) );
			}
		?>
	</div>
	<?php
}
else
{
	echo "No Results Found";
}
}
?>

Let me know how you get on, and if I can close this thread?