Code:
RuntimeException:
Failed to start the session: already started by PHP.
at vendor/symfony/http-foundation/Session/Storage/NativeSessionStorage.php:141
at Symfony\Component\HttpFoundation\Session\Storage\NativeSessionStorage->start()
(vendor/symfony/http-foundation/Session/Session.php:57)
at Symfony\Component\HttpFoundation\Session\Session->start()
(vendor/contao/core-bundle/src/Framework/ContaoFramework.php:181)
at Contao\CoreBundle\Framework\ContaoFramework->setConstants()
(vendor/contao/core-bundle/src/Framework/ContaoFramework.php:127)
at Contao\CoreBundle\Framework\ContaoFramework->initialize(true)
(vendor/contao/core-bundle/src/Routing/Matcher/LegacyMatcher.php:59)
at Contao\CoreBundle\Routing\Matcher\LegacyMatcher->matchRequest(object(Request))
(vendor/symfony-cmf/routing/src/DynamicRouter.php:271)
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:115)
at Symfony\Component\HttpKernel\EventListener\RouterListener->onKernelRequest(object(GetResponseEvent), 'kernel.request', object(EventDispatcher))
(vendor/symfony/event-dispatcher/EventDispatcher.php:212)
at Symfony\Component\EventDispatcher\EventDispatcher->doDispatch(array(array(object(DebugHandlersListener), 'configure'), array(object(ContentSecurityPolicyListener), 'onKernelRequest'), array(object(ValidateRequestListener), 'onKernelRequest'), array(object(CorsListener), 'onKernelRequest'), array(object(SessionListener), 'onKernelRequest'), array(object(FragmentListener), 'onKernelRequest'), array(object(CsrfTokenCookieListener), 'onKernelRequest'), array(object(RouterListener), 'onKernelRequest'), array(object(ResolveControllerNameSubscriber), 'onKernelRequest'), array(object(LocaleListener), 'onKernelRequest'), array(object(RefererIdListener), 'onKernelRequest'), array(object(LocaleListener), 'onKernelRequest'), array(object(TranslatorListener), 'onKernelRequest'), array(object(TraceableFirewallListener), 'onKernelRequest'), array(object(BackendLocaleListener), 'onKernelRequest'), array(object(BypassMaintenanceListener), 'onKernelRequest'), array(object(MaintenanceListener), 'onKernelRequest'), array(object(InsecureInstallationListener), 'onKernelRequest'), array(object(ToggleViewListener), 'onKernelRequest'), array(object(UserSessionListener), 'onKernelRequest'), array(object(HeaderReplayListener), 'onKernelRequest')), 'kernel.request', object(GetResponseEvent))
(vendor/symfony/event-dispatcher/EventDispatcher.php:44)
at Symfony\Component\EventDispatcher\EventDispatcher->dispatch('kernel.request', object(GetResponseEvent))
(vendor/symfony/http-kernel/HttpKernel.php:126)
at Symfony\Component\HttpKernel\HttpKernel->handleRaw(object(Request), 1)
(vendor/symfony/http-kernel/HttpKernel.php:67)
at Symfony\Component\HttpKernel\HttpKernel->handle(object(Request), 1, true)
(vendor/symfony/http-kernel/Kernel.php:198)
at Symfony\Component\HttpKernel\Kernel->handle(object(Request))
(web/app_dev.php:83)
Und das steht im Log: