Admin - Settings - Security cannot be opened

Nextcloud version (eg, 20.0.5): 27.1.8
Operating system and version (eg, Ubuntu 20.04): webhosted
Apache or nginx version (eg, Apache 2.4.25): webhosted
PHP version (eg, 7.4): 8.3

The issue you are facing: Admin → Settings → Security can’t be open

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

Steps to replicate it:

  1. open Admin → Settings → Security

The output of your Nextcloud log in Admin > Logging:

Creation of dynamic property OCA\FirstRunWizard\Settings\Personal::$urlGenerator is deprecated at /www/htdocs/TOPSECRET/apps/firstrunwizard/lib/Settings/Personal.php#40
Creation of dynamic property OCA\FirstRunWizard\Settings\Personal::$urlGenerator is deprecated at /www/htdocs/TOPSECRET/apps/firstrunwizard/lib/Settings/Personal.php#40

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

<?php
$CONFIG = array (
  'instanceid' => 'SuperId',
  'passwordsalt' => 'SuperSecure',
  'secret' => 'SuperSecret',
  'trusted_domains' => 
  array (
    0 => 'ushur.bestof.world',
  ),
  'datadirectory' => '/www/htdocs/TOPSECRET/data',
  'dbtype' => 'mysql',
  'version' => '27.1.8.1',
  'overwrite.cli.url' => 'ushur.bestof.world',
  'dbname' => 'yes',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'yes',
  'dbpassword' => 'Password1',
  'installed' => true,
  'tempdirectory' => '/www/htdocs/TOPSECRET/data/tmp',
  'profile.enabled' => true,
  'default_language' => 'de',
  'default_locale' => 'de_DE',
  'default_phone_region' => 'DE',
  'versions_retention_obligation' => '90, auto',
  'account_manager.default_property_scope' => 
  array (
    'email' => 'v2-private',
    'displayname' => 'v2-local',
  ),
  'maintenance' => false,
  'theme' => '',
  'loglevel' => 0,
  'mail_smtpmode' => 'smtp',
  'mail_smtphost' => 'MyServer',
  'mail_sendmailmode' => 'smtp',
  'mail_smtpport' => '465',
  'mail_smtpsecure' => 'ssl',
  'mail_from_address' => 'yes',
  'mail_domain' => 'BestDomain.ever',
  'mail_smtpauth' => 1,
  'mail_smtpname' => 'yes@funny.world',
  'mail_smtppassword' => 'MyPassword',
  'updater.secret' => 'SuperSecret',
  'skeletondirectory' => '/www/htdocs/TOPSECRET/data/skeleton-neu',
);

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

Don't got that. It's webhosted

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.

{"reqId":"ZhhaNfR49fs2hSXTC_ZuEQAAixo","level":0,"time":"2024-04-11T21:46:29+00:00","remoteAddr":"95.223.39.107","user":"hol_admin_ingo","app":"PHP","method":"GET","url":"/index.php/settings/admin/security","message":"Creation of dynamic property OCA\\FirstRunWizard\\Settings\\Personal::$urlGenerator is deprecated at /www/htdocs/TOPSECRET/apps/firstrunwizard/lib/Settings/Personal.php#40","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:124.0) Gecko/20100101 Firefox/124.0","version":"27.1.8.1","data":{"app":"PHP"}}
{"reqId":"ZhhaNfR49fs2hSXTC_ZuEQAAixo","level":3,"time":"2024-04-11T21:46:29+00:00","remoteAddr":"95.223.39.107","user":"hol_admin_ingo","app":"index","method":"GET","url":"/index.php/settings/admin/security","message":"Exception thrown: Exception","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:124.0) Gecko/20100101 Firefox/124.0","version":"27.1.8.1","exception":{"Exception":"Exception","Message":"hash_hkdf(): Argument #2 ($key) cannot be empty in file '/www/htdocs/TOPSECRET/lib/private/Security/Crypto.php' line 160","Code":0,"Trace":[{"file":"/www/htdocs/TOPSECRET/lib/private/AppFramework/App.php","line":183,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[["OCA\\Settings\\Controller\\AdminSettingsController"],"index"]},{"file":"/www/htdocs/TOPSECRET/lib/private/Route/Router.php","line":315,"function":"main","class":"OC\\AppFramework\\App","type":"::","args":["OCA\\Settings\\Controller\\AdminSettingsController","index",["OC\\AppFramework\\DependencyInjection\\DIContainer"],["security","settings.AdminSettings.index"]]},{"file":"/www/htdocs/TOPSECRET/lib/base.php","line":1068,"function":"match","class":"OC\\Route\\Router","type":"->","args":["/settings/admin/security"]},{"file":"/www/htdocs/TOPSECRET/index.php","line":38,"function":"handleRequest","class":"OC","type":"::","args":[]}],"File":"/www/htdocs/TOPSECRET/lib/private/AppFramework/Http/Dispatcher.php","Line":169,"Previous":{"Exception":"ValueError","Message":"hash_hkdf(): Argument #2 ($key) cannot be empty","Code":0,"Trace":[{"file":"/www/htdocs/TOPSECRET/lib/private/Security/Crypto.php","line":160,"function":"hash_hkdf","args":["sha512",["SensitiveParameterValue"]]},{"file":"/www/htdocs/TOPSECRET/lib/private/Security/Crypto.php","line":134,"function":"decryptWithoutSecret","class":"OC\\Security\\Crypto","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/www/htdocs/TOPSECRET/apps/oauth2/lib/Settings/Admin.php","line":54,"function":"decrypt","class":"OC\\Security\\Crypto","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/www/htdocs/TOPSECRET/apps/settings/lib/Controller/CommonSettingsTrait.php","line":129,"function":"getForm","class":"OCA\\OAuth2\\Settings\\Admin","type":"->","args":[]},{"file":"/www/htdocs/TOPSECRET/apps/settings/lib/Controller/AdminSettingsController.php","line":83,"function":"formatSettings","class":"OCA\\Settings\\Controller\\AdminSettingsController","type":"->","args":[[[["OCA\\Settings\\Settings\\Admin\\Security"]],[["OCA\\Password_Policy\\Settings"],["OCA\\BruteForceSettings\\Settings\\IPWhitelist"]],[["OCA\\OAuth2\\Settings\\Admin"]]]]},{"file":"/www/htdocs/TOPSECRET/apps/settings/lib/Controller/CommonSettingsTrait.php","line":149,"function":"getSettings","class":"OCA\\Settings\\Controller\\AdminSettingsController","type":"->","args":["security"]},{"file":"/www/htdocs/TOPSECRET/apps/settings/lib/Controller/AdminSettingsController.php","line":68,"function":"getIndexResponse","class":"OCA\\Settings\\Controller\\AdminSettingsController","type":"->","args":["admin","security"]},{"file":"/www/htdocs/TOPSECRET/lib/private/AppFramework/Http/Dispatcher.php","line":230,"function":"index","class":"OCA\\Settings\\Controller\\AdminSettingsController","type":"->","args":["security"]},{"file":"/www/htdocs/TOPSECRET/lib/private/AppFramework/Http/Dispatcher.php","line":137,"function":"executeController","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[["OCA\\Settings\\Controller\\AdminSettingsController"],"index"]},{"file":"/www/htdocs/TOPSECRET/lib/private/AppFramework/App.php","line":183,"function":"dispatch","class":"OC\\AppFramework\\Http\\Dispatcher","type":"->","args":[["OCA\\Settings\\Controller\\AdminSettingsController"],"index"]},{"file":"/www/htdocs/TOPSECRET/lib/private/Route/Router.php","line":315,"function":"main","class":"OC\\AppFramework\\App","type":"::","args":["OCA\\Settings\\Controller\\AdminSettingsController","index",["OC\\AppFramework\\DependencyInjection\\DIContainer"],["security","settings.AdminSettings.index"]]},{"file":"/www/htdocs/TOPSECRET/lib/base.php","line":1068,"function":"match","class":"OC\\Route\\Router","type":"->","args":["/settings/admin/security"]},{"file":"/www/htdocs/TOPSECRET/index.php","line":38,"function":"handleRequest","class":"OC","type":"::","args":[]}],"File":"/www/htdocs/TOPSECRET/lib/private/Security/Crypto.php","Line":160},"CustomMessage":"Exception thrown: Exception"}}

What do you mean with “wehosted”? Have you installed the software on your own on a server hosted on the internet or are you using Nextcloud in a shared environment of a web hoster?

It’s not selfhosted. In Germany a webhosting by a webhoster is called webhosted.

In this case I would recommend to contact your web hoster, because they are very often disabling functions in their shared environments.