Background job failing at every page load

My NC log is displaying this core error every time a web page is loaded making a mess of my log .

From BUI;

Error: InvalidArgumentException: Invalid serialized command at <>
0. /var/www/nextcloud/lib/private/BackgroundJob/Job.php line 62
OC\Command\CommandJob->run("O:33:“OCA\Fil … }”)

  1. /var/www/nextcloud/lib/private/BackgroundJob/QueuedJob.php line 46
    OC\BackgroundJob\Job->execute(OC\BackgroundJob\JobList {}, OC\Log {})
  2. /var/www/nextcloud/cron.php line 148
    OC\BackgroundJob\QueuedJob->execute(OC\BackgroundJob\JobList {}, OC\Log {})

From logfile;

{“reqId”:“fRroZbkT92tupnn4oqHq”,“level”:3,“time”:“2021-03-28T15:32:44+00:00”,“remoteAddr”:“”,“user”:"–",“app”:“core”,“method”:“GET”,“url”:"/nextcloud/cron.php",“message”:{“Exception”:“InvalidArgumentException”,“Message”:“Invalid serialized command”,“Code”:0,“Trace”:[{“file”:"/var/www/nextcloud/lib/private/BackgroundJob/Job.php",“line”:62,“function”:“run”,“class”:“OC\Command\CommandJob”,“type”:"->",“args”:[“O:33:“OCA\Files_Versions\Command\Expire”:2:{s:43:”\u0000OCA\Files_Versions\Command\Expire\u0000fileName";s:42:"/Photos/2007/2007_11_Tday2007/HPIM3254.JPG";s:39:"\u0000OCA\Files_Versions\Command\Expire\u0000user";s:5:“scott”;}"]},{“file”:"/var/www/nextcloud/lib/private/BackgroundJob/QueuedJob.php",“line”:46,“function”:“execute”,“class”:“OC\BackgroundJob\Job”,“type”:"->",“args”:[{“class”:“OC\BackgroundJob\JobList”},{“class”:“OC\Log”}]},{“file”:"/var/www/nextcloud/cron.php",“line”:148,“function”:“execute”,“class”:“OC\BackgroundJob\QueuedJob”,“type”:"->",“args”:[{“class”:“OC\BackgroundJob\JobList”},{“class”:“OC\Log”}]}],“File”:"/var/www/nextcloud/lib/private/Command/CommandJob.php",“Line”:37,“CustomMessage”:“Error while running background job (class: OC\Command\CommandJob, arguments: O:33:“OCA\Files_Versions\Command\Expire”:2:{s:43:”\u0000OCA\Files_Versions\Command\Expire\u0000fileName";s:42:"/Photos/2007/2007_11_Tday2007/HPIM3254.JPG";s:39:"\u0000OCA\Files_Versions\Command\Expire\u0000user";s:5:“scott”;})"},“userAgent”:“Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36”,“version”:“”}

I’d like to upgrade NC but need to clean-up this before doing so.

Sorry to hear you’re facing problems :slightly_frowning_face: is for home/non-enterprise users. If you’re running a business, paid support can be accessed via where we can ensure your business keeps running smoothly.

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Nextcloud version (eg, 20.0.5): 19.0.6
Operating system and version (eg, Ubuntu 20.04): Ubuntu 18.04.5 LTS
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4.29
PHP version (eg, 7.4): 7.2.33

The issue you are facing:

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

Steps to replicate it:

The output of your Nextcloud log in Admin > Logging:


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


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


Turned out oc_jobs contained over 8600 entries mosttly associated with the version app which I stopped using long ago. Apparently, there was a corrupt one in the table somewhere (top?) that was casing cron.php to abend. Being the mysql hack that I am, I took the hammer to it and truncated the table.