Internal Server Error after update unraid/nextcloud docker

Nextcloud version (dunno was 18 before, container says nextcloud:latest):
Operating system and version (Unraid 6.8.1):
Apache or nginx version (???):
PHP version (???):

The issue you are facing:
I cannot start nextcloud anymore.
i use a nextcloud docker in unraid, and it download by default the nextcloud:latest whatever that is.
Please, need help to fix this. i will never press the update button again XD

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

Steps to replicate it:
Update nextcloud container

The output of your Nextcloud log in Admin > Logging:

??? this is the nextcloud log
https://gofile.io/d/XFAkBn
{"reqId":"CMTHqbkJMgmdWdX9ebtI","level":3,"time":"2020-12-01T21:21:46+00:00","remoteAddr":"192.168.1.99","user":"--","app":"index","method":"GET","url":"/","message":{"Exception":"Doctrine\\DBAL\\DBALException","Message":"Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2002] Connection refused","Code":0,"Trace":[{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php","line":1449,"function":"connect","class":"OC\\DB\\Connection","type":"->","args":[]},{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php","line":892,"function":"getWrappedConnection","class":"Doctrine\\DBAL\\Connection","type":"->","args":[]},{"file":"/var/www/html/lib/private/DB/Connection.php","line":202,"function":"executeQuery","class":"Doctrine\\DBAL\\Connection","type":"->","args":["SELECT * FROM `oc_appconfig`",[],[],null]},{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php","line":206,"function":"executeQuery","class":"OC\\DB\\Connection","type":"->","args":["SELECT * FROM `oc_appconfig`",[],[]]},{"file":"/var/www/html/lib/private/DB/QueryBuilder/QueryBuilder.php","line":217,"function":"execute","class":"Doctrine\\DBAL\\Query\\QueryBuilder","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":345,"function":"execute","class":"OC\\DB\\QueryBuilder\\QueryBuilder","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":110,"function":"loadConfigValues","class":"OC\\AppConfig","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":301,"function":"getApps","class":"OC\\AppConfig","type":"->","args":[]},{"file":"/var/www/html/lib/private/legacy/OC_App.php","line":949,"function":"getValues","class":"OC\\AppConfig","type":"->","args":[false,"installed_version"]},{"file":"/var/www/html/lib/private/Server.php","line":668,"function":"getAppVersions","class":"OC_App","type":"::","args":[]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":155,"function":"OC\\{closure}","class":"OC\\Server","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php","line":118,"function":"OC\\AppFramework\\Utility\\{closure}","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":122,"function":"offsetGet","class":"Pimple\\Container","type":"->","args":["OC\\Memcache\\Factory"]},{"file":"/var/www/html/lib/private/ServerContainer.php","line":156,"function":"query","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["OC\\Memcache\\Factory",true]},{"file":"/var/www/html/lib/private/Server.php","line":1677,"function":"query","class":"OC\\ServerContainer","type":"->","args":["OC\\Memcache\\Factory"]},{"file":"/var/www/html/lib/private/Server.php","line":1017,"function":"getMemCacheFactory","class":"OC\\Server","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":155,"function":"OC\\{closure}","class":"OC\\Server","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php","line":118,"function":"OC\\AppFramework\\Utility\\{closure}","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":122,"function":"offsetGet","class":"Pimple\\Container","type":"->","args":["OCP\\Lock\\ILockingProvider"]},{"file":"/var/www/html/lib/private/ServerContainer.php","line":156,"function":"query","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["OCP\\Lock\\ILockingProvider",true]},{"file":"/var/www/html/lib/private/Server.php","line":1977,"function":"query","class":"OC\\ServerContainer","type":"->","args":["OCP\\Lock\\ILockingProvider"]},{"file":"/var/www/html/lib/private/Files/View.php","line":118,"function":"getLockingProvider","class":"OC\\Server","type":"->","args":[]},{"file":"/var/www/html/lib/private/Server.php","line":395,"function":"__construct","class":"OC\\Files\\View","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":155,"function":"OC\\{closure}","class":"OC\\Server","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php","line":118,"function":"OC\\AppFramework\\Utility\\{closure}","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":122,"function":"offsetGet","class":"Pimple\\Container","type":"->","args":["OC\\Files\\Node\\HookConnector"]},{"file":"/var/www/html/lib/private/ServerContainer.php","line":156,"function":"query","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["OC\\Files\\Node\\HookConnector",true]},{"file":"/var/www/html/lib/private/Server.php","line":1324,"function":"query","class":"OC\\ServerContainer","type":"->","args":["OC\\Files\\Node\\HookConnector"]},{"file":"/var/www/html/lib/base.php","line":595,"function":"boot","class":"OC\\Server","type":"->","args":[]},{"file":"/var/www/html/lib/base.php","line":1091,"function":"init","class":"OC","type":"::","args":[]},{"file":"/var/www/html/index.php","line":35,"args":["/var/www/html/lib/base.php"],"function":"require_once"}],"File":"/var/www/html/lib/private/DB/Connection.php","Line":72,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36 Edg/87.0.664.41","version":"19.0.1.1"}
{"reqId":"CMTHqbkJMgmdWdX9ebtI","level":3,"time":"2020-12-01T21:21:46+00:00","remoteAddr":"192.168.1.99","user":"--","app":"core","method":"GET","url":"/","message":{"Exception":"Doctrine\\DBAL\\DBALException","Message":"Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2002] Connection refused","Code":0,"Trace":[{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php","line":1449,"function":"connect","class":"OC\\DB\\Connection","type":"->","args":[]},{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php","line":892,"function":"getWrappedConnection","class":"Doctrine\\DBAL\\Connection","type":"->","args":[]},{"file":"/var/www/html/lib/private/DB/Connection.php","line":202,"function":"executeQuery","class":"Doctrine\\DBAL\\Connection","type":"->","args":["SELECT * FROM `oc_appconfig`",[],[],null]},{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php","line":206,"function":"executeQuery","class":"OC\\DB\\Connection","type":"->","args":["SELECT * FROM `oc_appconfig`",[],[]]},{"file":"/var/www/html/lib/private/DB/QueryBuilder/QueryBuilder.php","line":217,"function":"execute","class":"Doctrine\\DBAL\\Query\\QueryBuilder","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":345,"function":"execute","class":"OC\\DB\\QueryBuilder\\QueryBuilder","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":110,"function":"loadConfigValues","class":"OC\\AppConfig","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":301,"function":"getApps","class":"OC\\AppConfig","type":"->","args":[]},{"file":"/var/www/html/lib/private/legacy/OC_App.php","line":949,"function":"getValues","class":"OC\\AppConfig","type":"->","args":[false,"installed_version"]},{"file":"/var/www/html/lib/private/Server.php","line":668,"function":"getAppVersions","class":"OC_App","type":"::","args":[]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":155,"function":"OC\\{closure}","class":"OC\\Server","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php","line":118,"function":"OC\\AppFramework\\Utility\\{closure}","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":122,"function":"offsetGet","class":"Pimple\\Container","type":"->","args":["OC\\Memcache\\Factory"]},{"file":"/var/www/html/lib/private/ServerContainer.php","line":156,"function":"query","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["OC\\Memcache\\Factory",true]},{"file":"/var/www/html/lib/private/Server.php","line":1677,"function":"query","class":"OC\\ServerContainer","type":"->","args":["OC\\Memcache\\Factory"]},{"file":"/var/www/html/lib/private/Server.php","line":1017,"function":"getMemCacheFactory","class":"OC\\Server","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":155,"function":"OC\\{closure}","class":"OC\\Server","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php","line":118,"function":"OC\\AppFramework\\Utility\\{closure}","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":122,"function":"offsetGet","class":"Pimple\\Container","type":"->","args":["OCP\\Lock\\ILockingProvider"]},{"file":"/var/www/html/lib/private/ServerContainer.php","line":156,"function":"query","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["OCP\\Lock\\ILockingProvider",true]},{"file":"/var/www/html/lib/private/Server.php","line":1977,"function":"query","class":"OC\\ServerContainer","type":"->","args":["OCP\\Lock\\ILockingProvider"]},{"file":"/var/www/html/lib/private/Files/View.php","line":118,"function":"getLockingProvider","class":"OC\\Server","type":"->","args":[]},{"file":"/var/www/html/lib/private/Server.php","line":395,"function":"__construct","class":"OC\\Files\\View","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":155,"function":"OC\\{closure}","class":"OC\\Server","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/3rdparty/pimple/pimple/src/Pimple/Container.php","line":118,"function":"OC\\AppFramework\\Utility\\{closure}","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/html/lib/private/AppFramework/Utility/SimpleContainer.php","line":122,"function":"offsetGet","class":"Pimple\\Container","type":"->","args":["OC\\Files\\Node\\HookConnector"]},{"file":"/var/www/html/lib/private/ServerContainer.php","line":156,"function":"query","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->","args":["OC\\Files\\Node\\HookConnector",true]},{"file":"/var/www/html/lib/private/Server.php","line":1324,"function":"query","class":"OC\\ServerContainer","type":"->","args":["OC\\Files\\Node\\HookConnector"]},{"file":"/var/www/html/lib/base.php","line":595,"function":"boot","class":"OC\\Server","type":"->","args":[]},{"file":"/var/www/html/lib/base.php","line":1091,"function":"init","class":"OC","type":"::","args":[]},{"file":"/var/www/html/index.php","line":35,"args":["/var/www/html/lib/base.php"],"function":"require_once"}],"File":"/var/www/html/lib/private/DB/Connection.php","Line":72,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36 Edg/87.0.664.41","version":"19.0.1.1"}
{"reqId":"CMTHqbkJMgmdWdX9ebtI","level":3,"time":"2020-12-01T21:21:46+00:00","remoteAddr":"192.168.1.99","user":"--","app":"core","method":"GET","url":"/","message":{"Exception":"Doctrine\\DBAL\\DBALException","Message":"Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2002] Connection refused","Code":0,"Trace":[{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php","line":1449,"function":"connect","class":"OC\\DB\\Connection","type":"->","args":[]},{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php","line":892,"function":"getWrappedConnection","class":"Doctrine\\DBAL\\Connection","type":"->","args":[]},{"file":"/var/www/html/lib/private/DB/Connection.php","line":202,"function":"executeQuery","class":"Doctrine\\DBAL\\Connection","type":"->","args":["SELECT * FROM `oc_appconfig`",[],[],null]},{"file":"/var/www/html/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Query/QueryBuilder.php","line":206,"function":"executeQuery","class":"OC\\DB\\Connection","type":"->","args":["SELECT * FROM `oc_appconfig`",[],[]]},{"file":"/var/www/html/lib/private/DB/QueryBuilder/QueryBuilder.php","line":217,"function":"execute","class":"Doctrine\\DBAL\\Query\\QueryBuilder","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":345,"function":"execute","class":"OC\\DB\\QueryBuilder\\QueryBuilder","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":110,"function":"loadConfigValues","class":"OC\\AppConfig","type":"->","args":[]},{"file":"/var/www/html/lib/private/AppConfig.php","line":301,"function":"getApps","class":"OC\\AppConfig","type":"->","args":[]},{"file":"/var/www/html/lib/private/legacy/OC_App.php","line":949,"function":"getValues","class":"OC\\AppConfig","type":"->","args":[false,"installed_version"]},{"file":"/var/www/html/lib/private/TemplateLayout.php","line":185,"function":"getAppVersions","class":"OC_App","type":"::","args":[]},{"file":"/var/www/html/lib/private/legacy/OC_Template.php","line":183,"function":"__construct","class":"OC\\TemplateLayout","type":"->","args":["error",""]},{"file":"/var/www/html/lib/private/Template/Base.php","line":132,"function":"fetchPage","class":"OC_Template","type":"->","args":[]},{"file":"/var/www/html/lib/private/legacy/OC_Template.php","line":332,"function":"printPage","class":"OC\\Template\\Base","type":"->","args":[]},{"file":"/var/www/html/index.php","line":63,"function":"printExceptionErrorPage","class":"OC_Template","type":"::","args":[{"__class__":"Doctrine\\DBAL\\DBALException"},500]}],"File":"/var/www/html/lib/private/DB/Connection.php","Line":72,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36 Edg/87.0.664.41","version":"19.0.1.1"}

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

<?php
$CONFIG = array (
  'htaccess.RewriteBase' => '/',
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'apps_paths' => 
  array (
    0 => 
    array (
      'path' => '/var/www/html/apps',
      'url' => '/apps',
      'writable' => false,
    ),
    1 => 
    array (
      'path' => '/var/www/html/custom_apps',
      'url' => '/custom_apps',
      'writable' => true,
    ),
  ),
  'instanceid' => 'oc6xldxkokio',
  'passwordsalt' => 'x/x',
  'secret' => 'x/x/x',
  'trusted_domains' => 
  array (
    0 => 'xxxxxx',
    1 => 'xxxxxxx',
    2 => 'xxxxxx',
  ),
  'datadirectory' => '/var/www/html/data',
  'dbtype' => 'mysql',
  'version' => '19.0.1.1',
  'overwrite.cli.url' => 'http://xxx.xxx.xxx.xxx:8995',
  'overwriteprotocol' => 'https',
  'dbname' => 'nextcloud18',
  'dbhost' => 'xxx.xxx.xxx.xxx:3306',
  'dbport' => '3306',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'xx',
  'dbpassword' => 'xx',
  'installed' => true,
  'maintenance' => false,
);

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

????????????