Routing requirement for "_locale" cannot be empty

Hallo zusammen,

ich habe in den letzten Tagen für einen Kunden Contao 3.5 mit Eclipse 9 und ChangeLanguage auf 4.9 aktualisiert. Das lief auch recht gut.

Ein Problem besteht aber bei der Mehrsprachigkeit und der jeweiligen Startseite zur Sprache.
Sobald ich in der prepend_locale auf true setze funktionieren die folgenden URLs nicht und es kommt zum Fehler:

www.example.de (hier hat die 3.5 Version automatisch auf www.example.de/de geleitet)
www.example.de/de (hier hat die 3.5 Version den content der startseite.html angezeigt)

Code:

---


InvalidArgumentException:
Routing requirement for "_locale" cannot be empty.

  at vendor/symfony/routing/Route.php:591
  at Symfony\Component\Routing\Route->sanitizeRequirement('_locale', '')
    (vendor/symfony/routing/Route.php:477)
  at Symfony\Component\Routing\Route->addRequirements(array('_locale' => ''))
    (vendor/symfony/routing/Route.php:57)
  at Symfony\Component\Routing\Route->__construct('/{_locale}/', array('_token_check' => true, '_controller' => 'Contao\\FrontendIndex::renderPage', '_scope' => 'frontend', '_locale' => '', 'pageModel' => object(PageModel)), array('_locale' => ''), array(), '', null, array())
    (vendor/contao/core-bundle/src/Routing/RouteProvider.php:296)
  at Contao\CoreBundle\Routing\RouteProvider->addRoutesForRootPage(object(PageModel), array('tl_page.1.root' => object(Route), 'tl_page.1.fallback' => object(Route), 'tl_page.1945.root' => object(Route), 'tl_page.1945.fallback' => object(Route), 'tl_page.2061.root' => object(Route), 'tl_page.2061.fallback' => object(Route), 'tl_page.2071.root' => object(Route), 'tl_page.2071.fallback' => object(Route), 'tl_page.2163.root' => object(Route), 'tl_page.2163.fallback' => object(Route), 'tl_page.2254.root' => object(Route), 'tl_page.2254.fallback' => object(Route), 'tl_page.2345.root' => object(Route), 'tl_page.2345.fallback' => object(Route), 'tl_page.2437.root' => object(Route), 'tl_page.2437.fallback' => object(Route)))
    (vendor/contao/core-bundle/src/Routing/RouteProvider.php:220)
  at Contao\CoreBundle\Routing\RouteProvider->addRoutesForRootPages(array(object(PageModel), object(PageModel), object(PageModel), object(PageModel), object(PageModel), object(PageModel), object(PageModel), object(PageModel), object(PageModel), object(PageModel)), array('tl_page.1.root' => object(Route), 'tl_page.1.fallback' => object(Route), 'tl_page.1945.root' => object(Route), 'tl_page.1945.fallback' => object(Route), 'tl_page.2061.root' => object(Route), 'tl_page.2061.fallback' => object(Route), 'tl_page.2071.root' => object(Route), 'tl_page.2071.fallback' => object(Route), 'tl_page.2163.root' => object(Route), 'tl_page.2163.fallback' => object(Route), 'tl_page.2254.root' => object(Route), 'tl_page.2254.fallback' => object(Route), 'tl_page.2345.root' => object(Route), 'tl_page.2345.fallback' => object(Route), 'tl_page.2437.root' => object(Route), 'tl_page.2437.fallback' => object(Route)))
    (vendor/contao/core-bundle/src/Routing/RouteProvider.php:70)
  at Contao\CoreBundle\Routing\RouteProvider->getRouteCollectionForRequest(object(Request))
    (vendor/contao/core-bundle/src/Routing/LegacyRouteProvider.php:43)
  at Contao\CoreBundle\Routing\LegacyRouteProvider->getRouteCollectionForRequest(object(Request))
    (vendor/symfony-cmf/routing/src/NestedMatcher/NestedMatcher.php:140)
  at Symfony\Cmf\Component\Routing\NestedMatcher\NestedMatcher->matchRequest(object(Request))
    (vendor/contao/core-bundle/src/Routing/Matcher/LegacyMatcher.php:69)
  at Contao\CoreBundle\Routing\Matcher\LegacyMatcher->matchRequest(object(Request))
    (vendor/symfony-cmf/routing/src/DynamicRouter.php:278)
  at Symfony\Cmf\Component\Routing\DynamicRouter->matchRequest(object(Request))
    (vendor/symfony-cmf/routing/src/ChainRouter.php:188)
  at Symfony\Cmf\Component\Routing\ChainRouter->doMatch('/', object(Request))
    (vendor/symfony-cmf/routing/src/ChainRouter.php:158)
  at Symfony\Cmf\Component\Routing\ChainRouter->matchRequest(object(Request))
    (vendor/symfony/http-kernel/EventListener/RouterListener.php:112)
  at Symfony\Component\HttpKernel\EventListener\RouterListener->onKernelRequest(object(RequestEvent), 'kernel.request', object(TraceableEventDispatcher))
    (vendor/symfony/event-dispatcher/Debug/WrappedListener.php:126)
  at Symfony\Component\EventDispatcher\Debug\WrappedListener->__invoke(object(RequestEvent), 'kernel.request', object(TraceableEventDispatcher))
    (vendor/symfony/event-dispatcher/EventDispatcher.php:264)
  at Symfony\Component\EventDispatcher\EventDispatcher->doDispatch(array(object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener)), 'kernel.request', object(RequestEvent))
    (vendor/symfony/event-dispatcher/EventDispatcher.php:239)
  at Symfony\Component\EventDispatcher\EventDispatcher->callListeners(array(object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener)), 'kernel.request', object(RequestEvent))
    (vendor/symfony/event-dispatcher/EventDispatcher.php:73)
  at Symfony\Component\EventDispatcher\EventDispatcher->dispatch(object(RequestEvent), 'kernel.request')
    (vendor/symfony/event-dispatcher/Debug/TraceableEventDispatcher.php:168)
  at Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcher->dispatch(object(RequestEvent), 'kernel.request')
    (vendor/symfony/http-kernel/HttpKernel.php:134)
  at Symfony\Component\HttpKernel\HttpKernel->handleRaw(object(Request), 1)
    (vendor/symfony/http-kernel/HttpKernel.php:80)
  at Symfony\Component\HttpKernel\HttpKernel->handle(object(Request), 1, true)
    (vendor/symfony/http-kernel/Kernel.php:201)
  at Symfony\Component\HttpKernel\Kernel->handle(object(Request))
    (web/index.php:31)

---

Die folgenden Urls wiederum funktionieren einwandfrei:

www.example.de/de/startseite.html
www.example.de/en/main.html
...


Hat jemand eine Idee wo der Fehler liegen könnte?

Das Problem konnte ich nun beheben.

Schuld an dem ganzen war eine unveröffentlichte Seitenstruktur die als Vorlage für weitere Strukturen angelegt wurde. Bei dieser Struktur war keine Sprache zugewiesen und somit kam beim Routing eine leeres _locale an :D