boxes.disregard_removed_handlers.patch

diff --git boxes.module boxes.module
index b2bd65a..e89166f 100644
--- boxes.module
+++ boxes.module
@@ -321,8 +321,11 @@ function boxes_box_load($delta = NULL) {
   $boxes = array();
   foreach (ctools_export_load_object('box') as $box) {
     $box = boxes_box::load($box->delta);
-    drupal_alter('boxes_box_load', $box, $delta);
-    $boxes[$box->delta] = $box;
+    // Disregard boxes in the database whose handler has since been removed
+    if (isset($box->delta)) {
+      drupal_alter('boxes_box_load', $box, $delta);
+      $boxes[$box->delta] = $box;
+    }
   }
   return $boxes;
 }