Index: modules/field/field.crud.inc
===================================================================
RCS file: /cvs/drupal/drupal/modules/field/field.crud.inc,v
retrieving revision 1.61
diff -u -p -r1.61 field.crud.inc
--- modules/field/field.crud.inc	31 May 2010 07:59:27 -0000	1.61
+++ modules/field/field.crud.inc	3 Jun 2010 01:41:25 -0000
@@ -704,14 +704,14 @@ function field_update_instance($instance
   // Check that the specified field exists.
   $field = field_read_field($instance['field_name']);
   if (empty($field)) {
-    throw new FieldException("Attempt to update an instance of a nonexistent field.");
+    throw new FieldException(t('Attempt to update an instance of a nonexistent field @field.', array('@field' => $instance['field_name'])));
   }
 
   // Check that the field instance exists (even if it is inactive, since we
   // want to be able to replace inactive widgets with new ones).
   $prior_instance = field_read_instance($instance['entity_type'], $instance['field_name'], $instance['bundle'], array('include_inactive' => TRUE));
   if (empty($prior_instance)) {
-    throw new FieldException("Attempt to update a field instance that doesn't exist.");
+    throw new FieldException(t("Attempt to update an instance of field @field on bundle @bundle that doesn't exist.", array('@field' => $instance['field_name'], '@bundle' => $instance['bundle'])));
   }
 
   $instance['id'] = $prior_instance['id'];