I am getting the error:

May 29 19:15:02 vps3.domain.com crond[19846]: pam_limits(crond:session): invalid line 'user3 hard nproc ' - skipped
May 29 19:15:02 vps3.domain.com crond[19846]: pam_limits(crond:sess:on): invalid line 'user4 hard nproc ' - skipped

The cron line is:

* * * * * /usr/local/bin/php /home/user3/public_html/api/crons/cron-mailer.php

I have tried many solutions from stacks and nothing works.

I’ve tried:

1. Adding on /etc/security/limits.conf

   root soft nproc 200000

   root hard nproc 200000

2. sysctl1 -w fs.file-max=200000

The restarting the cron but I still get the above errors on systemctl status crond

What’s the solution to this problem as I cannot run any crons at all?