- in _field_ui_field_overview_form_validate_add_new()

      // Field name already exists. We need to check inactive fields as well, so
      // we can't use field_fields().
      module_load_include('inc', 'content', 'includes/content.crud');
      $fields = field_read_fields(array(), TRUE);
      $used = FALSE;
      foreach ($fields as $existing_field) {
        $used |= ($existing_field['field_name'] == $field_name);
      }
      if ($used) {
        form_set_error('_add_new_field][field_name', t('Add new field: the field name %field_name already exists.', array('%field_name' => $field_name)));
      }
      
becomes

      // Field name already exists. We need to check inactive fields as well, so
      // we can't use field_info_fields().
      $fields = field_read_fields(array('field_name' => $field_name), array('include_inactive' => TRUE));
      if ($fields) {
        form_set_error('_add_new_field][field_name', t('Add new field: the field name %field_name already exists.', array('%field_name' => $field_name)));
      }
    }
    
- in field_ui_field_overview_form_submit()
      drupal_set_message(t('There was a problem creating field %label: @message.', array(
      '%label' => $values['label'], '@message' => $e->getMessage())));
becomes
      drupal_set_message(t('There was a problem creating field %label: @message.', array(
        '%label' => $instance['label'], '@message' => $e->getMessage())));

and 
      drupal_set_message(t('The field %label cannot be added because it is locked.', array('%label' => $field['field_name'])));
becomes
      drupal_set_message(t('The field %label cannot be added because it is locked.', array('%label' => $values['label'])));

and
        drupal_set_message(t('There was a problem creating field instance %label: @message.', array(
      '%label' => $field['label'], '@message' => $e->getMessage())));
becomes
        drupal_set_message(t('There was a problem creating field instance %label: @message.', array(
          '%label' => $instance['label'], '@message' => $e->getMessage())));
      
- field_ui_field_remove_form_submit becomes

function field_ui_field_remove_form_submit($form, &$form_state) {
  $form_values = $form_state['values'];
  $field = field_info_field($form_values['field_name']);
  $instance = field_info_instance($form_values['field_name'], $form_values['bundle']);
  $bundles = field_info_bundles();
  $bundle = $form_values['bundle'];
  $bundle_label = $bundles[$bundle]['label'];

  if (!empty($bundle) && $field && !$field['locked'] && $form_values['confirm']) {
    field_delete_instance($field['field_name'], $bundle);
    // Delete the field if that was the last instance.
    if (count($field['bundles'] == 1)) {
      field_delete_field($field['field_name']);
    }
    drupal_set_message(t('The field %field has been removed from %type.', array('%field' => $instance['label'], '%type' => $bundle_label)));
  }
  else {
    drupal_set_message(t('There was a problem removing the %field from %type.', array('%field' => $instance['label'], '%type' => $bundle_label)));
  }
  $form_state['redirect'] = field_ui_next_destination($bundle);
}