NC12.0 upgrade from 11.03
Ubuntu 16.04
Apache 2.4.18-2ubuntu3.2 
mysql Ver 5.7.18-0ubuntu0.16.04.1 
php  7.0.18-0ubuntu0.16.04.1
apps installed:

  - activity: 2.5.2
  - admin_audit: 1.2.0
  - admin_notifications: 1.0.0
  - announcementcenter: 3.1.0
  - bruteforcesettings: 1.0.2
  - calendar: 1.5.3
  - circles: 0.10.0
  - comments: 1.2.0
  - contacts: 1.5.3
  - dav: 1.3.0
  - external: 2.0.2
  - federatedfilesharing: 1.2.0
  - federation: 1.2.0
  - files: 1.7.2
  - files_automatedtagging: 1.2.2
  - files_external: 1.3.0
  - files_pdfviewer: 1.1.1
  - files_retention: 1.1.2
  - files_sharing: 1.4.0
  - files_texteditor: 2.4.1
  - files_trashbin: 1.2.0
  - files_versions: 1.5.0
  - files_videoplayer: 1.1.0
  - firstrunwizard: 2.1
  - gallery: 17.0.0
  - logreader: 2.0.0
  - lookup_server_connector: 1.0.0
  - nextcloud_announcements: 1.1
  - notes: 2.2.0
  - notifications: 2.0.0
  - oauth2: 1.0.5
  - password_policy: 1.2.2
  - provisioning_api: 1.2.0
  - serverinfo: 1.2.0
  - sharebymail: 1.2.0
  - spreed: 2.0.1
  - survey_client: 1.0.0
  - systemtags: 1.2.0
  - tasks: 0.9.5
  - theming: 1.3.0
  - twofactor_backupcodes: 1.1.1
  - updatenotification: 1.2.0
  - workflowengine: 1.2.0
Disabled:
  - activitylog
  - encryption
  - files_antivirus
  - user_external
  - user_ldap


{
    "system": {
        "instanceid": "xx",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "xx",
            "xx",
            "xx",
            "xx"
        ],
        "datadirectory": "\/data",
        "overwrite.cli.url": "https:\/\/www.xx",
        "dbtype": "mysql",
        "version": "12.0.0.29",
        "dbname": "xx",
        "dbhost": "xx",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "logtimezone": "Europe\/Berlin",
        "installed": true,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "filelocking.enabled": "true",
        "redis": {
            "host": "\/var\/run\/redis\/redis.sock",
            "port": 0,
            "timeout": 0
        },
        "session_lifetime": 3600,
        "htaccess.RewriteBase": "\/xx",
        "mail_smtpmode": "smtp",
        "mail_smtpsecure": "ssl",
        "mail_from_address": "noReply",
        "mail_domain": "xx.nl",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpauth": 1,
        "mail_smtphost": "smtp.xx.com",
        "mail_smtpport": "465",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "loglevel": 0,
        "cron_log": true,
        "log_rotate_size": 104857600,
        "enable_previews": true,
        "enabledPreviewProviders": [
            "OC\\Preview\\PNG",
            "OC\\Preview\\JPEG",
            "OC\\Preview\\GIF",
            "OC\\Preview\\BMP",
            "OC\\Preview\\XBitmap",
            "OC\\Preview\\MarkDown",
            "OC\\Preview\\MP3",
            "OC\\Preview\\TXT",
            "OC\\Preview\\Movie"
        ],
        "preview_max_filesize_image": 200,
        "updater.secret": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "theme": "",
        "singleuser": true,
        "updater.release.channel": "stable"
    }
}


config.php
<?php
$CONFIG = array (
  'instanceid' => 'xx,
  'passwordsalt' => 'xx',
  'secret' => 'xx',
  'trusted_domains' =>
  array (
    0 => 'xx',
    1 => 'xx',
    2 => 'xx',
    3 => 'xx',
  ),
  'datadirectory' => '/data',
  'overwrite.cli.url' => 'https://www.xx',
  'dbtype' => 'mysql',
  'version' => '12.0.0.29',
  'dbname' => 'xx',
  'dbhost' => 'xx',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'xx',
  'dbpassword' => 'xx',
  'logtimezone' => 'Europe/Berlin',
  'installed' => true,
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'filelocking.enabled' => 'true',
  'redis' =>
  array (
    'host' => '/var/run/redis/redis.sock',
    'port' => 0,
    'timeout' => 0.0,
  ),
  'session_lifetime' => 3600,
  'htaccess.RewriteBase' => '/xx',
  'mail_smtpmode' => 'smtp',
  'mail_smtpsecure' => 'ssl',
  'mail_from_address' => 'noReply',
  'mail_domain' => 'xx.nl',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_smtpauth' => 1,
  'mail_smtphost' => 'smtp.xx.com',
  'mail_smtpport' => 'xx',
  'mail_smtpname' => 'NoReply@xx.nl',
  'mail_smtppassword' => 'xxxx',
  'loglevel' => 0,
  'cron_log' => true,
  'log_rotate_size' => 104857600,
  'enable_previews' => true,
  'enabledPreviewProviders' =>
  array (
    0 => 'OC\\Preview\\PNG',
    1 => 'OC\\Preview\\JPEG',
    2 => 'OC\\Preview\\GIF',
    3 => 'OC\\Preview\\BMP',
    4 => 'OC\\Preview\\XBitmap',
    5 => 'OC\\Preview\\MarkDown',
    6 => 'OC\\Preview\\MP3',
    7 => 'OC\\Preview\\TXT',
    8 => 'OC\\Preview\\Movie',
  ),
  'preview_max_filesize_image' => 200,
  'updater.secret' => 'xx',
  'maintenance' => false,
  'theme' => '',
  'singleuser' => true,
  'updater.release.channel' => 'stable',
);