Nextcloud version 14.0.6:
Ubuntu Desktop 18.10:
Apache version 2.4.34:
PHP version 7.2:
I recently renewed my certificate from Lets’ encrypt as well as upgrading the OS to Ubuntu 18.10 (The same day)
The problem I am currently facing is that every night the Apache server is making a Graceful restart and then the nextcloud instance is not reachable anymore (" This site can’t be reached"). I have tried the command “sudo service apache2 reload” which cause the same issue. The root of my webserver is still accessible but not “/nextcloud”.
Thank you in advance 
The output of your Nextcloud log in Admin > Logging:
I have cleared the log and reproduced the error but the log is still empty.
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
<?php
$CONFIG = array (
'instanceid' => 'oc4pevi79l9q',
'overwrite.cli.url' => 'xxxxxxxxxx',
'passwordsalt' => 'xxxxxxxxxxxxx',
'secret' => 'xxxxxxxxxxxxxxxxx',
'trusted_domains' =>
array (
0 => 'xxxxxxxxxxxx',
1 => '192.168.0.15',
),
'datadirectory' => '/var/www/nextcloud/data',
'dbtype' => 'mysql',
'version' => '14.0.6.0',
'dbname' => 'nextcloud',
'dbhost' => 'localhost',
'dbport' => '',
'dbtableprefix' => 'oc_',
'mysql.utf8mb4' => true,
'dbuser' => 'root',
'dbpassword' => 'xxxxxxxxx',
'installed' => true,
'theme' => '',
'loglevel' => 2,
'maintenance' => false,
'debug' => false,
'htaccess.RewriteBase' => '/nextcloud',
'auth.bruteforce.protection.enabled' => false,
'ldapIgnoreNamingRules' => false,
'ldapProviderFactory' => '\\OCA\\User_LDAP\\LDAPProviderFactory',
'mail_from_address' => 'admin',
'mail_smtpmode' => 'php',
'mail_smtpauthtype' => 'LOGIN',
'mail_domain' => 'xxxxxxxxx',
'memcache.local' => '\\OC\\Memcache\\APCu',
'memcache.locking' => '\\OC\\Memcache\\Redis',
'filelocking.enabled' => 'true',
'redis' =>
array (
'host' => '/var/run/redis/redis-server.sock',
'port' => 0,
'timeout' => 0.0,
),
'updater.release.channel' => 'stable',
'enable_previews' => true,
'enabledPreviewProviders' =>
array (
0 => 'OC\\Preview\\Image',
1 => 'OC\\Preview\\MP3',
2 => 'OC\\Preview\\TXT',
3 => 'OC\\Preview\\PDF',
4 => 'OC\\Preview\\Movie',
5 => 'OC\\Preview\\Photoshop',
6 => 'OC\\Preview\\TIFF',
7 => 'OC\\Preview\\SVG',
8 => 'OC\\Preview\\OpenDocument',
),
);
The output of your Apache/nginx/system log in /var/log/____:
[Sun Jan 20 15:26:01.688914 2019] [mpm_prefork:notice] [pid 19644] AH00163: Apache/2.4.34 (Ubuntu) OpenSSL/1.1.1 configured -- resuming normal operations
[Sun Jan 20 15:26:01.688946 2019] [core:notice] [pid 19644] AH00094: Command line: '/usr/sbin/apache2'
[Sun Jan 20 15:26:02.697844 2019] [core:notice] [pid 19644] AH00051: child pid 19678 exit signal Segmentation fault (11), possible coredump in /var/cache/apache2
[Sun Jan 20 15:26:02.697894 2019] [core:notice] [pid 19644] AH00051: child pid 19680 exit signal Segmentation fault (11), possible coredump in /var/cache/apache2
[Sun Jan 20 15:26:02.697901 2019] [core:error] [pid 19644] AH00546: no record of generation 0 of exiting child 19680
[Sun Jan 20 15:26:02.697914 2019] [core:notice] [pid 19644] AH00051: child pid 19682 exit signal Segmentation fault (11), possible coredump in /var/cache/apache2
[Sun Jan 20 15:26:02.697920 2019] [core:error] [pid 19644] AH00546: no record of generation 0 of exiting child 19682
[Sun Jan 20 15:26:02.697932 2019] [core:notice] [pid 19644] AH00051: child pid 19684 exit signal Segmentation fault (11), possible coredump in /var/cache/apache2
[Sun Jan 20 15:26:02.697938 2019] [core:error] [pid 19644] AH00546: no record of generation 0 of exiting child 19684
[Sun Jan 20 15:26:02.697949 2019] [core:notice] [pid 19644] AH00051: child pid 19686 exit signal Segmentation fault (11), possible coredump in /var/cache/apache2
[Sun Jan 20 15:26:02.697955 2019] [core:error] [pid 19644] AH00546: no record of generation 0 of exiting child 19686