Nextcloud could not reach the server

Nextcloud version (eg, 10.0.2): 11.0.2
Operating system and version (eg, Ubuntu 16.04): debian jessie
Apache or nginx version (eg, Apache 2.4.25): Apache/2.4.10
PHP version (eg, 5.6): 7.0.18-1~dotdeb+8.1
Is this the first time you’ve seen this error?: yes

Can you reliably replicate it? (If so, please outline steps): i don’t try to reinstall or replicate the failure

The issue you are facing:
I installed the nextcloud on my root-server, and was finish with the first steps an my first login to the nextcloud.
I activated or was in the step to aktivate the crypt security an i would install the app for the encryption but it can not reach the app-servers.
so i tryed to ping nextcloud.com from my root-server and there is 100% packet loss… but the server is still online and i can ping it from outsite and i can ping other sites e.g. google.com or other servers from my root so there musst be a blockade from my rootserver to the nextcloud servers?
I can’t download the encryption module or load any other modules into my nextcloud installation and the failure says all the time there ino connection to the internet but it is!

The output of your Nextcloud log in Admin > Logging:
Error internet_connection_check OC\Encryption\Exceptions\ModuleDoesNotExistsException: No default encryption module defined

/var/www/nextcloud/lib/private/Encryption/Manager.php - line 201: OC\Encryption\Manager->getDefaultEncryptionModule()
/var/www/nextcloud/lib/private/Files/Storage/Wrapper/Encryption.php - line 1015: OC\Encryption\Manager->getEncryptionModule()
/var/www/nextcloud/lib/private/Files/Storage/Wrapper/Encryption.php - line 447: OC\Files\Storage\Wrapper\Encryption->shouldEncrypt('files_external/...')
/var/www/nextcloud/lib/private/Files/Storage/LocalTempFileTrait.php - line 66: OC\Files\Storage\Wrapper\Encryption->fopen('files_external/...', 'r')
/var/www/nextcloud/lib/private/Files/Storage/LocalTempFileTrait.php - line 49: OC\Files\Storage\Wrapper\Encryption->toTmpFile('files_external/...')
/var/www/nextcloud/lib/private/Files/Storage/Wrapper/Encryption.php - line 778: OC\Files\Storage\Wrapper\Encryption->getCachedFile('files_external/...')
/var/www/nextcloud/lib/private/Files/Storage/Wrapper/Wrapper.php - line 360: OC\Files\Storage\Wrapper\Encryption->getLocalFile('files_external/...')
/var/www/nextcloud/lib/private/Files/View.php - line 239: OC\Files\Storage\Wrapper\Wrapper->getLocalFile('files_external/...')
/var/www/nextcloud/lib/private/Security/CertificateManager.php - line 226: OC\Files\View->getLocalFile('/files_external...')
/var/www/nextcloud/lib/private/Http/Client/Client.php - line 74: OC\Security\CertificateManager->getAbsoluteBundlePath(NULL)
/var/www/nextcloud/lib/private/Http/Client/Client.php - line 136: OC\Http\Client\Client->setDefaultOptions()
/var/www/nextcloud/settings/Controller/CheckSetupController.php - line 124: OC\Http\Client\Client->get('http //www.gith...')
/var/www/nextcloud/settings/Controller/CheckSetupController.php - line 107: OC\Settings\Controller\CheckSetupController->isSiteReachable('www.github.com')
/var/www/nextcloud/settings/Controller/CheckSetupController.php - line 363: OC\Settings\Controller\CheckSetupController->isInternetConnectionWorking()
[internal function] OC\Settings\Controller\CheckSetupController->check()
/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 160: call_user_func_array(Array, Array)
/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php - line 90: OC\AppFramework\Http\Dispatcher->executeController(Object(OC\Settings\Controller\CheckSetupController), 'check')
/var/www/nextcloud/lib/private/AppFramework/App.php - line 114: OC\AppFramework\Http\Dispatcher->dispatch(Object(OC\Settings\Controller\CheckSetupController), 'check')
/var/www/nextcloud/lib/private/AppFramework/Routing/RouteActionHandler.php - line 47: OC\AppFramework\App main('OC\\Settings\\Con...', 'check', Object(OC\AppFramework\DependencyInjection\DIContainer), Array)
[internal function] OC\AppFramework\Routing\RouteActionHandler->__invoke(Array)
/var/www/nextcloud/lib/private/Route/Router.php - line 299: call_user_func(Object(OC\AppFramework\Routing\RouteActionHandler), Array)
/var/www/nextcloud/lib/base.php - line 1010: OC\Route\Router->match('/settings/ajax/...')
/var/www/nextcloud/index.php - line 40: OC handleRequest()
{main}

2017-04-17T14:51:44+0200

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

<?php $CONFIG = array ( 'memcache.distributed' => '\OC\Memcache\Memcached', 'memcached_servers' => array( array('localhost', 11211), ), 'instanceid' => 'id-secret', 'passwordsalt' => 'stay-secret', 'secret' => '.......stay-secret...........', 'trusted_domains' => array ( 0 => 'my-cloud-domain', ), 'datadirectory' => '/srv/nextcloud/data', 'overwrite.cli.url' => 'https://my-cloud-domain', 'dbtype' => 'mysql', 'version' => '11.0.2.7', 'dbname' => 'user', 'dbhost' => 'localhost', 'dbport' => '', 'dbtableprefix' => 'oc_', 'dbuser' => 'database', 'dbpassword' => 'password', 'logtimezone' => 'UTC', 'installed' => true, ); The output of your Apache/nginx/system log in `/var/log/____`: this logfile looks normal there might be no error wich is reasonable for the issue here Hope that the information can help to find the problem..... i think there musst be an blockade of my server ip/domain to nextcloud.com thats why it doesn't work to load apps or to get the full funktionality of the cloud