Navigate to any page that contains an embedded image popup.
Observe the error message displayed on the page.
Symfony\Component\Routing\Exception\RouteNotFoundException: Route "image_popup.image_popup_render_original" does not exist. in Drupal\Core\Routing\RouteProvider->getRouteByName() (line 208 of core/lib/Drupal/Core/Routing/RouteProvider.php)