Admin Settings Inaccessible

After upgrading nextcloud using the web updater I can no longer access the admin user settings page

Nextcloud version (eg, 18.0.2): 20.0.3.2
Operating system and version (eg, Ubuntu 20.04): Raspbian (Debian Buster 10)
Apache or nginx version (eg, Apache 2.4.25): 2.4.38-3+deb10u4 armhf
PHP version (eg, 7.1):7.3

The issue you are facing:

After upgrading nextcloud using the web updater I can no longer access the admin user settings page

http://pi.hole:8080/nextcloud/index.php/settings/user:

`The server was unable to complete your request.

If this happens again, please send the technical details below to the server administrator.

More details can be found in the server log.

### Technical details

*** Remote Address: 192.168.2.43**
*** Request ID: patmNa06uyII6ibfZE2j**`

Is this the first time you’ve seen this error? Y

Steps to replicate it:

  1. Upgrade to the latest stable release of nextcloud

The output of your Nextcloud log in Admin > Logging:

**I can no longer access this.**

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

<?php
$CONFIG = array (
  'instanceid' => 'ocb6hi7c9s44',
  'passwordsalt' => 'xxx',
  'secret' => 'xxx',
  'trusted_domains' =>
  array (
    0 => 'pi.hole:8080',
  ),
  'datadirectory' => '/data/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '20.0.3.2',
  'overwrite.cli.url' => 'http://pi.hole:8080/nextcloud',
  'dbname' => 'nextclouddb',
  'dbhost' => 'localhost:3306',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'nextcloud',
  'dbpassword' => 'xxx',
  'installed' => true,
  'memcache.local' => '\\OC\\Memcache\\Redis',
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'redis' =>
  array (
    'host' => 'localhost',
    'port' => 6379,
  ),
  'updater.secret' => '$2y$10$wSCbqCwLhHC9Jpd7gLStiuSYHbuXjfwqg3OUgNKnnCq2G/VVUXjcu',
  'maintenance' => false,
  'theme' => '',
  'loglevel' => 2,
);

Access Log

PASTE HERE

As already written in the error message, you should check the Nextcloud server log file for any related and more detailed error messages. In most cases an administrator has forgotten to install a required php module. So please also check the requirements.