--- geocoder.widget.inc	2018-05-13 21:02:06.000000000 +0800
+++ geocoder.widget.inc	2018-06-21 09:11:35.000000000 +0800
@@ -354,7 +354,12 @@
   }
   else if ($entity) {
     $wrapper = entity_metadata_wrapper($entity_type, $entity);
-    $field_wrapper = $wrapper->value()->$field_name;
+    if (!empty($wrapper->value()->$field_name)) {
+      $field_wrapper = $wrapper->value()->$field_name;
+    }
+    else {
+      return FALSE;
+    }
     $value = $field_wrapper[LANGUAGE_NONE];
     $values = array_filter(is_array($value) && isset($value[0]) ? $value : array($value));
     $source_field_values = array_map(function($value) {