"Dieses Verzeichnis ist nicht verfügbar" / no more files and directories via browser

Nextcloud version (eg, 20.0.5): 24.0.1snap1
Operating system and version (eg, Ubuntu 20.04): 20.04.4 LTS (GNU/Linux 5.4.0-120-generic x86_64)
Apache or nginx version (eg, Apache 2.4.25): how do i get this out of snap?!
PHP version (eg, 7.4): PHP 7.4.3 (cli) (built: Jun 13 2022 13:43:30) ( NTS ) ; backend GUI states Version: 8.0.20

The issue you are facing:
after (auto)updating to 24.0.1snap1 all users cannot see nor acess any files over the browser webinterface. Whereas clients sync (on all platforms) still work.

found similiar topics from a few years back, tried the occ filescan, which simply stops without further explanation after 2 of 92 users, see

 sudo nextcloud.occ files:scan --all -vvv
Starting scan for user 1 out of 91 (admin)
        Folder  /admin/
        Folder  /admin/files_versions
        Folder  /admin/files_versions/Documents
        File    /admin/files_versions/Documents/About.odt.v1590363107
        File    /admin/files_versions/Documents/About.odt.v1571179538
        File    /admin/files_versions/Documents/About.odt.v1590366774
        Folder  /admin/uploads
        Folder  /admin/files
        File    /admin/files/Nextcloud Manual.pdf
        File    /admin/files/Nextcloud.mp4
        File    /admin/files/Nextcloud.png
        Folder  /admin/files/Documents
        File    /admin/files/Documents/Nextcloud Flyer.pdf
        File    /admin/files/Documents/About.txt
        File    /admin/files/Documents/About.odt
        Folder  /admin/files/Photos
        File    /admin/files/Photos/Coast.jpg
        File    /admin/files/Photos/Nut.jpg
        File    /admin/files/Photos/Nextcloud Community.jpg
        File    /admin/files/Photos/Hummingbird.jpg
        Folder  /admin/files/Talk
        Folder  /admin/files_trashbin
        Folder  /admin/files_trashbin/files
        Folder  /admin/cache

Starting scan for user 2 out of 91 (alina.m)
        Folder  /alina.m/
        Folder  /alina.m/files_versions
        Folder  /alina.m/files
        File    /alina.m/files/Nextcloud Manual.pdf
        File    /alina.m/files/Nextcloud.png
        File    /alina.m/files/Nextcloud intro.mp4
        Folder  /alina.m/files/Documents
        File    /alina.m/files/Documents/Example.md
        File    /alina.m/files/Documents/Readme.md
        File    /alina.m/files/Documents/Example.odt
        File    /alina.m/files/Documents/Nextcloud flyer.pdf
        Folder  /alina.m/files/Photos
        File    /alina.m/files/Photos/Nextcloud community.jpg
        File    /alina.m/files/Photos/Vineyard.jpg
        File    /alina.m/files/Photos/Steps.jpg
        File    /alina.m/files/Photos/Gorilla.jpg
        File    /alina.m/files/Photos/Toucan.jpg
        File    /alina.m/files/Photos/Frog.jpg
        File    /alina.m/files/Photos/Birdie.jpg
        File    /alina.m/files/Photos/Readme.md
        File    /alina.m/files/Photos/Library.jpg
        Folder  /alina.m/files/Talk
        Folder  /alina.m/cache
#

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

Steps to replicate it:
haven’t tried yet.

The output of your Nextcloud log in Admin > Logging:

[PHP] Fehler: Allowed memory size of 536870912 bytes exhausted (tried to allocate 4096 bytes) at /snap/nextcloud/31033/htdocs/lib/private/Files/Cache/Wrapper/CacheJail.php#310

GET /ocs/v2.php/search/providers/files/search?term=apa&from=%2Fsettings%2Fadmin%2Fserverinfo
from 192.168.187.1 by daniel at 2022-06-20T18:58:06+00:00

[PHP] Fehler: Allowed memory size of 536870912 bytes exhausted (tried to allocate 4096 bytes) at /snap/nextcloud/31033/htdocs/lib/private/Files/Cache/Wrapper/CacheJail.php#310

GET /index.php/apps/files/api/v1/recent
from 192.168.187.1 by mona.weniger at 2022-06-20T16:31:59+00:00

The output of your config.php file in /path/to/nextcloud:

<?php
$CONFIG = array (
  'apps_paths' =>
  array (
    0 =>
    array (
      'path' => '/snap/nextcloud/current/htdocs/apps',
      'url' => '/apps',
      'writable' => false,
    ),
    1 =>
    array (
      'path' => '/var/snap/nextcloud/current/nextcloud/extra-apps',
      'url' => '/extra-apps',
      'writable' => true,
    ),
  ),
  'supportedDatabases' =>
  array (
    0 => 'mysql',
  ),
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'memcache.local' => '\\OC\\Memcache\\Redis',
  'redis' =>
  array (
    'host' => '/tmp/sockets/redis.sock',
    'port' => 0,
  ),
  'passwordsalt' => 'xxx',
  'secret' => 'xxx',
  'trusted_domains' =>
  array (
    0 => 'localhost',
    1 => 'xxx',
    2 => 'xxx',
    3 => '192.168.187.22',
  ),
  'datadirectory' => '/var/snap/nextcloud/common/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '24.0.1.1',
  'overwrite.cli.url' => 'https://cloud.xxx.org',
  'overwriteprotocol' => 'https',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost:/tmp/sockets/mysql.sock',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'nextcloud',
  'dbpassword' => 'xxx',
  'installed' => true,
  'instanceid' => 'ocqojfve4pa1',
  'mail_from_address' => 'sonnencloud',
  'mail_smtpmode' => 'smtp',
  'mail_sendmailmode' => 'smtp',
  'mail_domain' => 'xxx',
  'mail_smtpsecure' => 'ssl',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_smtpauth' => 1,
  'mail_smtphost' => 'xxx',
  'mail_smtpport' => '465',
  'mail_smtpname' => 'x',
  'mail_smtppassword' => 'xxx',
  'maintenance' => false,
  'theme' => '',
  'loglevel' => 0,
  'allow_local_remote_servers' => true,
  'app_install_overwrite' =>
  array (
    0 => 'circles',
    1 => 'external',
    2 => 'spreed',
  ),
);

The output of your Apache/nginx/system log in /var/log/____:
don’t know which log you want exactly :x

sudo snap logs nextcloud.apache
2022-06-20T00:00:02Z nextcloud.apache[643277]: Certificates look to be in order: enabling HSTS
2022-06-20T00:00:02Z nextcloud.apache[643277]: HTTP compression is disabled
2022-06-20T00:00:03Z nextcloud.apache[643370]: AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message
2022-06-20T00:00:03Z systemd[1]: Reloaded Service for snap application nextcloud.apache.
2022-06-20T00:00:10Z systemd[1]: Reloading Service for snap application nextcloud.apache.
2022-06-20T00:00:10Z nextcloud.apache[643634]: Certificates have been activated: using HTTPS only
2022-06-20T00:00:10Z nextcloud.apache[643634]: Certificates look to be in order: enabling HSTS
2022-06-20T00:00:10Z nextcloud.apache[643634]: HTTP compression is disabled
2022-06-20T00:00:10Z nextcloud.apache[643714]: AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message
2022-06-20T00:00:10Z systemd[1]: Reloaded Service for snap application nextcloud.apache.

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.

see above