Files not loading

Nextcloud version (eg, 12.0.2): 14.03
Operating system and version (eg, Ubuntu 17.04): Debian 4.9.130-2
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4.25 nginx/1.13.8
PHP version (eg, 7.1): PHP 7.2.12-1+0~20181112102304.11+stretch~1.gbp55f215

The issue you are facing: This is the first time I’m installing Nextcloud on Plesk, but I already installed Nextcloud on a normal VPS once or twice.
Ok: The issue I’m facing is, that the files are not loading. There is just this loading animation and noting is happenig. I think I can use everything else (settings and apps seems to work).
Also the log thing is spammed with this “You are using a fallback implementation of the intl extension. Installing the native one is highly recommended instead. at /var/www/vhosts/” error.

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

Steps to replicate it:

  1. I
  2. Don’t
  3. Know

The output of your Nextcloud log in Admin > Logging:

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

$CONFIG = array (
  'instanceid' => '*****',
  'passwordsalt' => '*****',
  'secret' => '*****',
  'trusted_domains' => 
  array (
    0 => 'cloud.<IP>.net',
  'datadirectory' => '/var/www/vhosts/<IP>.net/cloud.<IP>.net/data',
  'dbtype' => 'mysql',
  'version' => '',
  'overwrite.cli.url' => 'https://cloud.<IP>.nett/nextcloud',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'nextcloud',
  'dbpassword' => '*****',
  'installed' => true,

The output of your Apache log in /var/log/apache2/error.log:

The output of your Apache log in /var/log/nginx/error.log:

2018/11/18 12:12:40 [emerg] 8632#0: unexpected end of file, expecting "}" in /var/www/vhosts/system/