Sometimes error from running cron job

Nextcloud version : 24.0.1
Operating system and version : debian bullseye
Apache or nginx version : apache 2.4.53-1
PHP version : 7.4.29

The issue you are facing:

running cron throws an error - but only sometimes

from the logs

{"reqId":"0Kj3kj2KDBJwEjhsGBf4","level":3,"time":"2022-05-31T16:15:03+00:00","remoteAddr":"","user":"--","app":"cron","method":"","url":"--","message":"Call to a member function getPath() on null","userAgent":"--","version":"24.0.1.1","e
xception":{"Exception":"Error","Message":"Call to a member function getPath() on null","Code":0,"Trace":[{"file":"/var/www/webs/ambar/DOMAIN/lib/private/Encryption/Update.php","line":107,"function":"getPath","class":"OC\\Fi
les\\Filesystem","type":"::"},{"file":"/var/www/webs/ambar/DOMAIN/lib/private/Encryption/HookManager.php","line":40,"function":"postUnshared","class":"OC\\Encryption\\Update","type":"->"},{"file":"/var/www/webs/ambar/DOMAIN/lib/private/legacy/OC_Hook.php","line":106,"function":"postUnshared","class":"OC\\Encryption\\HookManager","type":"::"},{"file":"/var/www/webs/ambar/DOMAIN/lib/private/Share20/LegacyHooks.php","line":84,"func
tion":"emit","class":"OC_Hook","type":"::"},{"file":"/var/www/webs/ambar/DOMAIN/3rdparty/symfony/event-dispatcher/EventDispatcher.php","line":264,"function":"postUnshare","class":"OC\\Share20\\LegacyHooks","type":"->"},{"fi
le":"/var/www/webs/ambar/DOMAIN/3rdparty/symfony/event-dispatcher/EventDispatcher.php","line":239,"function":"doDispatch","class":"Symfony\\Component\\EventDispatcher\\EventDispatcher","type":"->"},{"file":"/var/www/webs/am
bar/DOMAIN/3rdparty/symfony/event-dispatcher/EventDispatcher.php","line":73,"function":"callListeners","class":"Symfony\\Component\\EventDispatcher\\EventDispatcher","type":"->"},{"file":"/var/www/webs/ambar/DOMAIN/lib/private/EventDispatcher/SymfonyAdapter.php","line":122,"function":"dispatch","class":"Symfony\\Component\\EventDispatcher\\EventDispatcher","type":"->"},{"file":"/var/www/webs/ambar/DOMAIN/lib/private/Share20/Mana
ger.php","line":1247,"function":"dispatch","class":"OC\\EventDispatcher\\SymfonyAdapter","type":"->"},{"file":"/var/www/webs/ambar/DOMAIN/lib/private/Share20/Manager.php","line":1555,"function":"deleteShare","class":"OC\\Sh
are20\\Manager","type":"->"},{"file":"/var/www/webs/ambar/DOMAIN/lib/private/Share20/Manager.php","line":1456,"function":"checkExpireDate","class":"OC\\Share20\\Manager","type":"->"},{"file":"/var/www/webs/ambar/DOMAIN/apps/files_sharing/lib/ExpireSharesJob.php","line":99,"function":"getShareById","class":"OC\\Share20\\Manager","type":"->"},{"file":"/var/www/webs/ambar/DOMAIN/lib/public/BackgroundJob/Job.php","line":79,"function
":"run","class":"OCA\\Files_Sharing\\ExpireSharesJob","type":"->"},{"file":"/var/www/webs/ambar/DOMAIN/lib/public/BackgroundJob/TimedJob.php","line":95,"function":"execute","class":"OCP\\BackgroundJob\\Job","type":"->"},{"f
ile":"/var/www/webs/ambar/DOMAIN/cron.php","line":151,"function":"execute","class":"OCP\\BackgroundJob\\TimedJob","type":"->"}],"File":"/var/www/webs/ambar/DOMAIN/lib/private/Files/Filesystem.php","Line":795,"
CustomMessage":"--"}}

cron output

Error: Call to a member function getPath() on null in /var/www/webs/ambar/DOMAIN/lib/private/Files/Filesystem.php:795
Stack trace:
#0 /var/www/webs/ambar/DOMAIN/lib/private/Encryption/Update.php(107): OC\Files\Filesystem::getPath()
#1 /var/www/webs/ambar/DOMAIN/lib/private/Encryption/HookManager.php(40): OC\Encryption\Update->postUnshared()
#2 /var/www/webs/ambar/DOMAIN/lib/private/legacy/OC_Hook.php(106): OC\Encryption\HookManager::postUnshared()
#3 /var/www/webs/ambar/DOMAIN/lib/private/Share20/LegacyHooks.php(84): OC_Hook::emit()
#4 /var/www/webs/ambar/DOMAIN/3rdparty/symfony/event-dispatcher/EventDispatcher.php(264): OC\Share20\LegacyHooks->postUnshare()
#5 /var/www/webs/ambar/DOMAIN/3rdparty/symfony/event-dispatcher/EventDispatcher.php(239): Symfony\Component\EventDispatcher\EventDispatcher->doDispatch()
#6 /var/www/webs/ambar/DOMAIN/3rdparty/symfony/event-dispatcher/EventDispatcher.php(73): Symfony\Component\EventDispatcher\EventDispatcher->callListeners()
#7 /var/www/webs/ambar/DOMAIN/lib/private/EventDispatcher/SymfonyAdapter.php(122): Symfony\Component\EventDispatcher\EventDispatcher->dispatch()
#8 /var/www/webs/ambar/DOMAIN/lib/private/Share20/Manager.php(1247): OC\EventDispatcher\SymfonyAdapter->dispatch()
#9 /var/www/webs/ambar/DOMAIN/lib/private/Share20/Manager.php(1555): OC\Share20\Manager->deleteShare()
#10 /var/www/webs/ambar/DOMAIN/lib/private/Share20/Manager.php(1456): OC\Share20\Manager->checkExpireDate()
#11 /var/www/webs/ambar/DOMAIN/apps/files_sharing/lib/ExpireSharesJob.php(99): OC\Share20\Manager->getShareById()
#12 /var/www/webs/ambar/DOMAIN/lib/public/BackgroundJob/Job.php(79): OCA\Files_Sharing\ExpireSharesJob->run()
#13 /var/www/webs/ambar/DOMAIN/lib/public/BackgroundJob/TimedJob.php(95): OCP\BackgroundJob\Job->execute()
#14 /var/www/webs/ambar/DOMAIN/cron.php(151): OCP\BackgroundJob\TimedJob->execute()
#15 {main}

Is this the first time you’ve seen this error? : N

Steps to replicate it:

sometimes running

*/15 *   * * *   ambar      /usr/bin/php7.4 -f /var/www/webs/ambar/DOMAIN/cron.php --define apc.enable_cli=1

The output of your Nextcloud log in Admin > Logging:

I pasted it a few lines before

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

<?php
$CONFIG = array (
  'instanceid' => '*****',
  'passwordsalt' => '*****',
  'secret' => '*****',
  'trusted_domains' =>
  array (
    0 => 'DOMAIN',
  ),
  'datadirectory' => '/var/www/webs/ambar/DOMAIN/data',
  'dbtype' => 'mysql',
  'version' => '24.0.1.1',
  'overwrite.cli.url' => 'https://DOMAIN',
  'dbname' => 'ambarsql2',
  'dbhost' => 'localhost',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'mysql.utf8mb4' => true,
  'dbuser' => 'ambarsql2',
  'dbpassword' => '*****',
  'installed' => true,
  'default_phone_region' => 'DE',
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'mail_from_address' => 'nextcloud',
  'mail_smtpmode' => 'smtp',
  'mail_sendmailmode' => 'smtp',
  'mail_domain' => 'DOMAIN',
  'mail_smtphost' => 'localhost',
  'mail_smtpport' => '25',
  'app_install_overwrite' =>
  array (
    0 => 'bruteforcesettings',
  ),
  'maintenance' => false,
  'theme' => '',
  'loglevel' => 3,
);

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

no errors at moment of cron job is running