is_dir(): open_basedir restriction in effect. File(/var/lib/php/session) is not within the allowed path(s): (/var/www/vhosts/server.com/:/tmp/).
Trace:
#0 [internal function]: Whoops\Run->handleError(2, 'is_dir(): open_...', '/var/www/vhosts...', 51, Array) #1 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/Session/Storage/Handler/NativeFileSessionHandler.php(51): is_dir('/var/lib/php/se...') #2 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Session/Session.php(34): Symfony\Component\HttpFoundation\Session\Storage\Handler\NativeFileSessionHandler->__construct() #3 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Session/SessionServiceProvider.php(15): Concrete\Core\Session\Session::start() #4 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/vendor/illuminate/container/Illuminate/Container/Container.php(498): Concrete\Core\Session\SessionServiceProvider->Concrete\Core\Session\{closure}(Object(Concrete\Core\Application\Application), Array) #5 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/vendor/illuminate/container/Illuminate/Container/Container.php(425): Illuminate\Container\Container->build(Object(Closure), Array) #6 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/vendor/illuminate/container/Illuminate/Container/Container.php(809): Illuminate\Container\Container->make('session') #7 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Support/Facade/Facade.php(43): Illuminate\Container\Container->offsetGet('session') #8 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Support/Facade/Facade.php(105): Concrete\Core\Support\Facade\Facade::resolveFacadeInstance('session') #9 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/User/User.php(203): Concrete\Core\Support\Facade\Facade::__callStatic('has', Array) #10 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/User/User.php(203): Concrete\Core\Support\Facade\Session::has('uID') #11 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/User/User.php(52): Concrete\Core\User\User->__construct() #12 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Package/StartingPointPackage.php(341): Concrete\Core\User\User::getByUserID(1, true, false) #13 [internal function]: Concrete\Core\Package\StartingPointPackage->add_users() #14 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/controllers/install.php(264): call_user_func(Array) #15 [internal function]: Concrete\Controller\Install->run_routine('elemental_full', 'add_users') #16 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Controller/AbstractController.php(156): call_user_func_array(Array, Array) #17 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Routing/ControllerRouteCallback.php(25): Concrete\Core\Controller\AbstractController->runAction('run_routine', Array) #18 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Routing/Router.php(59): Concrete\Core\Routing\ControllerRouteCallback->execute(Object(Concrete\Core\Http\Request), Object(Concrete\Core\Routing\Route), Array) #19 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Support/Facade/Facade.php(119): Concrete\Core\Routing\Router->execute(Object(Concrete\Core\Routing\Route), Array) #20 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Application/Application.php(366): Concrete\Core\Support\Facade\Facade::__callStatic('execute', Array) #21 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/src/Application/Application.php(366): Concrete\Core\Support\Facade\Route::execute(Object(Concrete\Core\Routing\Route), Array) #22 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/bootstrap/start.php(217): Concrete\Core\Application\Application->dispatch(Object(Concrete\Core\Http\Request)) #23 /var/www/vhosts/server.com/concrete.server.com/concrete/concrete/dispatcher.php(36): require('/var/www/vhosts...') #24 /var/www/vhosts/server.com/concrete.server.com/concrete/index.php(2): require('/var/www/vhosts...') #25 {main}

print_r( ini_get('open_basedir') );
/*
returns
/var/www/vhosts/server.com/:/tmp/
*/