Views row style plugin override not saving in Views UI In my ongoing journey to create a customized RSS feed in my D8 site, I've finally gotten closest to what I need by using a Feed display in Views. The basic feed is working, but I need to add a couple custom elements for each item. So based on the fact that the rss fields are rendered in the RSSFields class (\Drupal\views\Plugin\views\row)

namespace Drupal\video_export\Plugin\views\row;

use Drupal\views\Plugin\views\row;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Url;

/**
 * Renders an RSS item based on fields.
 *
 * @ViewsRow(
 *   id = "mycustom_rss_fields",
 *   title = @Translation("My Custom Fields"),
 *   help = @Translation("Display fields as RSS items."),
 *   theme = "views_view_row_rss",
 *   display_types = {"feed"}
 * )
 */
class MyCustomRssFields extends RssFields {


  public function render($row) {
    parent::render();  



  }
}


So when I place this in /modules/custom/video_export/src/Plugin/views/row, if I go to select the style, I see my new plugin, but when I click Apply, nothing happens. Is there anything else I need to add to my override to get it to save?
The issue was an incomplete namespace in the use statement for the RssFields class. I had

use Drupal\views\Plugin\views\row;


so it was looking for that class in my module. Changing it to 

use Drupal\views\Plugin\views\row\RssFields;


made everything work.