Index: wp-includes/template-loader.php
===================================================================
--- wp-includes/template-loader.php	(revision 21916)
+++ wp-includes/template-loader.php	(working copy)
@@ -39,7 +39,10 @@
 	else :
 		$template = get_index_template();
 	endif;
-	if ( $template = apply_filters( 'template_include', $template ) )
+	if ( $template = apply_filters( 'template_include', $template ) ){
 		include( $template );
+	}else{
+		wp_die( "Whoops! Looks like your theme is missing." );
+	}	
 	return;
 endif;