Nextcloud version: 25.0.2
Operating system and version: unRAID 6.11.1, nextcloud Linuxserver Docker
nginx version: 2.9.18
PHP version: no idea 
The issue you are facing:
I can’t reach my Nextcloud anymore. It stopped working from one day to another, can’t recall I changed anything (like updating a Docker). Can’t tell when it happened exactly, I just noticed from my PC having a grey icon instead of the green.
Trying to reach it gives a “ERR_CONNECTION_TIMED_OUT” in Chrome.
I run the linuxserver Nextcloud Docker on my unRAID, mariaDB as database and nginx as DynDNS Service. The DynDNS is from my personal domain. I setup a test DynDNS to check nginx functionality, which works fine.
Ports in my router are still set and work fine 
The Docker runs and docker-logs show no errors, same for mariaDB, nginx says it’s “online”.
I’m not good with anything Linux so I have a hardtime finding all the files and info needed, hopefully I can make due I have no idea what to do
Is this the first time you’ve seen this error? (Y/N): Y
The output of your Nextcloud log in Admin > Logging:
as I can't access nextcloud, I can't get the log
The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
<?php
$CONFIG = array (
'memcache.local' => '\\OC\\Memcache\\APCu',
'datadirectory' => '/data',
'instanceid' => 'ocme13n05qve',
'passwordsalt' => 'redacted',
'secret' => 'redacted',
'trusted_domains' =>
array (
0 => '192.168.178.8', # unraid ip within my network
1 => 'redacted', #my dyndns
),
'dbtype' => 'mysql',
'version' => '25.0.2.3',
'overwrite.cli.url' => 'https://192.168.178.8',
'overwritehost' => 'redacted', #my dnydns
'overwriteprotocol' => 'https',
'dbname' => 'redacted',
'dbhost' => '192.168.178.8:3306', #mariaDB port
'dbport' => '',
'dbtableprefix' => 'oc_',
'mysql.utf8mb4' => true,
'dbuser' => 'redacted',
'dbpassword' => 'redacted',
'installed' => true,
'default_phone_region' => 'DE',
'mail_domain' => 'redacted',
'mail_from_address' => 'redacted',
'mail_smtpmode' => 'smtp',
'mail_sendmailmode' => 'smtp',
'mail_smtpsecure' => 'tls',
'mail_smtphost' => 'redacted',
'mail_smtpport' => '25',
'mail_smtpauthtype' => 'LOGIN',
'mail_smtpauth' => 1,
'mail_smtpname' => 'redacted',
'mail_smtppassword' => 'redacted',
'maintenance' => false,
'loglevel' => 2,
'theme' => '',
'updater.release.channel' => 'stable',
);
The output of your Apache/nginx/system log in /var/log/____:
I'm not sure where to find it; ...\nextcloud\log\nginx has access and error logs (the latter being empty)
Output errors in nextcloud.log in /var/www/ or as admin user in top right menu, filtering for errors. Use a pastebin service if necessary.
I can't find that file either; Documentation says it's in the "data" folder, I don't have that folder anywhere :( tried to use the filesearch in my appdata (where Docker data sits), but no dice