--- ./pathfilter_original/pathfilter.module	2010-02-19 15:34:25.000000000 -0800
+++ ./pathfilter/pathfilter.module	2010-03-30 18:25:38.000000000 -0700
@@ -231,7 +231,11 @@ function _pathfilter_replace_links(&$nod
     while ($row = db_fetch_object($result)) {
       $defined_formats[] = $row->format;
     }
-
+    // If no filters were set, issue configuration warning
+    if (empty($defined_formats)) {
+      drupal_set_message(t('No filters were configured for Path Filter. Please configure an Input Format to use Path Filter.'), 'warning');
+      return;
+    }
     // Iterate through our objects properties looking for body, teaser, and any fields that have
     // formatting defined for them.
     foreach ($node as $key => &$value) {