Administration - Installation - Core: Re(9): Problem in ilias6 Installation

"For an error free installation use composer 1.9.3"

What did you do after installation of composer 1.9.3?

I did systemctl restart apache2

I'm still getting errors like: "include(Services/GlobalScreen/artifacts/global_screen_providers.php): failed to open stream: No such file or directory"
when I want to login in my fresh ILIAS 6v installtion.

###### error-logs
Whoops\Exception\ErrorException thrown with message "include(Services/GlobalScreen/artifacts/global_screen_providers.php): failed to open stream: No such file or directory"

Stacktrace:
#8 Whoops\Exception\ErrorException in /var/www/ilias/Services/GlobalScreen/classes/class.ilGSProviderFactory.php:49
#7 include in /var/www/ilias/Services/GlobalScreen/classes/class.ilGSProviderFactory.php:49
#6 ilGSProviderFactory:__construct in /var/www/ilias/Services/Init/classes/class.ilInitialisation.php:1395
#5 ilInitialisation:{closure} in /var/www/ilias/libs/composer/vendor/pimple/pimple/src/Pimple/Container.php:118
#4 Pimple\Container:offsetGet in /var/www/ilias/src/DI/Container.php:176
#3 ILIAS\DI\Container:globalScreen in /var/www/ilias/Services/Init/classes/class.ilInitialisation.php:1397
#2 ilInitialisation:initGlobalScreen in /var/www/ilias/Services/Init/classes/class.ilInitialisation.php:1258
#1 ilInitialisation:initClient in /var/www/ilias/Services/Init/classes/class.ilInitialisation.php:1052
#0 ilInitialisation:initILIAS in /var/www/ilias/login.php:22
#######


Solution, for all which are not that familiar with composer like me. (https://bbs-ilias.de/ilias/goto.php?target=pg_46_187&client_id=info)
cd /var/www/html/ilias
composer install --no-dev