diff --git modules/field/field.attach.inc modules/field/field.attach.inc
index 59c91f9..1ef3202 100644
--- modules/field/field.attach.inc
+++ modules/field/field.attach.inc
@@ -436,6 +436,24 @@ function _field_invoke_get_instances($entity_type, $bundle, $options) {
     }
   }
 
+  $invalid_instances = array();
+  foreach ($instances as $key => $instance) {
+    if (!isset($instance['field_name']) || !isset($instance['field_id'])) {
+      $invalid_instances[] = $instance;
+      unset($instances[$key]);
+    }
+  }
+  if ($invalid_instances) {
+    $callstack = debug_backtrace();
+    debug($callstack[1]['function'], 'caller');
+    debug($entity_type, 'entity type');
+    debug($bundle, 'bundle');
+    debug($options, 'options');
+    foreach ($invalid_instances as $instance) {
+      debug($instance, 'instance');
+    }
+  }
+
   return $instances;
 }