Upgraded from Nextcloud 14 to 16 and cannot access my cloud

Nextcloud version (eg, 12.0.2): cannot tell as I cannot access my nextcloud. Should be newest
Operating system and version (eg, Ubuntu 17.04): shared hosting (netcup.de)
Apache or nginx version (eg, Apache 2.4.25): unkown
PHP version (eg, 7.1): 7.2.19

The issue you are facing:

I can’t access my nextcloud after upgrading and trying to activate the emoji support.

Is this the first time you’ve seen this error? (Y/N): Y

The output of your Nextcloud log in Admin > Logging:


Interner Serverfehler

Der Server konnte die Anfrage nicht fertig stellen.

Sollte dies erneut auftreten, sende bitte die nachfolgenden technischen Einzelheiten an Deinen Server-Administrator.

Weitere Details können im Server-Protokoll gefunden werden.
Technische Details

    Entfernte Adresse: *****
    Anfragekennung: 9UJSogsxz5545d0HZzUb
    Typ: OCP\Files\NotPermittedException
    Code: 0
    Nachricht: Could not create path
    Datei: /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/Files/Node/Folder.php
    Zeile: 185


Trace

#0 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/Files/SimpleFS/SimpleFolder.php(83): OC\Files\Node\Folder->newFile('b583-8deb-serve...')
#1 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/Template/SCSSCacher.php(273): OC\Files\SimpleFS\SimpleFolder->newFile('b583-8deb-serve...')
#2 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/Template/SCSSCacher.php(153): OC\Template\SCSSCacher->cache('/var/www/vhosts...', 'b583-8deb-serve...', 'server.scss', Object(OC\Files\SimpleFS\SimpleFolder), '/core/css')
#3 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/Template/CSSResourceLocator.php(109): OC\Template\SCSSCacher->process('/var/www/vhosts...', 'core/css/server...', 'core')
#4 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/Template/CSSResourceLocator.php(61): OC\Template\CSSResourceLocator->cacheAndAppendScssIfExist('/var/www/vhosts...', 'core/css/server...')
#5 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/Template/ResourceLocator.php(78): OC\Template\CSSResourceLocator->doFind('css/server')
#6 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/TemplateLayout.php(296): OC\Template\ResourceLocator->find(Array)
#7 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/TemplateLayout.php(201): OC\TemplateLayout::findStylesheetFiles(Array)
#8 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/legacy/template.php(183): OC\TemplateLayout->__construct('guest', '')
#9 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/Template/Base.php(131): OC_Template->fetchPage()
#10 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/private/legacy/template.php(273): OC\Template\Base->printPage()
#11 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/base.php(676): OC_Template::printGuestPage('', 'error', Array)
#12 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/lib/base.php(1056): OC::init()
#13 /var/www/vhosts/hosting114110.a2f63.netcup.net/httpdocs/nextcloud/index.php(40): require_once('/var/www/vhosts...')
#14 {main}


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

<?php
$CONFIG = array (
  'instanceid' => 'ocwpol65g4n3',
  'passwordsalt' => '**********',
  'secret' => '**********',
  'trusted_domains' =>
  array (
    0 => 'mynas.bid',
    1 => '******',
  ),
  'datadirectory' => '/ncdata',
  'overwrite.cli.url' => 'https://mynas.bid',
  'dbtype' => 'mysql',
  'version' => '16.0.3.0',
  'dbname' => 'k30807_nextcloud',
  'dbhost' => '10.35.47.100',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => '********',
  'dbpassword' => '********',
  'installed' => true,
  'filelocking.enabled' => 'true',
  'htaccess.RewriteBase' => '/',
  'mail_smtpmode' => 'smtp',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_from_address' => 'noreply',
  'mail_domain' => 'mynas.bid',
  'mail_smtpauth' => 1,
  'mail_smtphost' => '*******',
  'mail_smtpport' => '465',
  'mail_smtpname' => '********',
  'mail_smtppassword' => '********',
  'mail_smtpsecure' => 'ssl',
  'maintenance' => false,
  'theme' => '',
  'loglevel' => '7',
  'updater.release.channel' => 'production',
  'updater.secret' => '********',
  'debug' => true,
  'mysql.utf8mb4' => true,
);

The output of your Apache/nginx/system log in /var/log/____:

PASTE HERE