Problem/Motivation
After updating from Drupal core 10.3.10 to 10.4.0, I get an error message for the following three admin pages:
/admin/appearance
Notification: Symfony\Component\Routing\Exception\RouteNotFoundException: Route "update.theme_install" does not exist. in Drupal\Core\Routing\RouteProvider->getRouteByName() (line 211 of /web/core/lib/Drupal/Core/Routing/RouteProvider.php).
/admin/modules
Notification: Symfony\Component\Routing\Exception\RouteNotFoundException: Route "update.module_install" does not exist. in Drupal\Core\Routing\RouteProvider->getRouteByName() (line 211 of /web/core/lib/Drupal/Core/Routing/RouteProvider.php).
/reports/updates
Notification: Symfony\Component\Routing\Exception\RouteNotFoundException: Route "update.report_install" does not exist. in Drupal\Core\Routing\RouteProvider->getRouteByName() (line 211 of /web/core/lib/Drupal/Core/Routing/RouteProvider.php).
Steps to reproduce
I did the update manually, i.e. without composer. (The website is completely installed without composer.)
The subsequent database update ran without errors.