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Sorry to hear you’re facing problems 
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Nextcloud version (eg, 16.0.1):
Operating system and version (eg, slackware 14.2):
Apache or nginx version (eg, nginx 1.15.12 ):
PHP version (eg, 7.3.4):
The issue you are facing:
Is this the first time you’ve seen this error? (Y/N):
Steps to replicate it:
- Change the setting of cronjob of nextcloud (cron.php) in the crontab to */5 * * * * (from 15mins to 5mins)
- login as admin to nextcloud, and goto Settings->Basic Settings
- at Background jobs section, it still report
Use system cron service to call the cron.php file every 15 minutes. The cron.php needs to be executed by the system user “user”.
I check that the cronjob (cron.php) runs every 5 mins, but, for example, the Activity email is sent out every 15mins instead of 5mins.
Just want to ask is there any parameter I need to change in the config.php to set the background job interval?
Thanks!