Ubuntu 20.04 LEMP + Virtualmin 6.14 / Webmin 1.970
(installed with sh /root/virtualmin-install.sh -b LEMP -m)
(everything updated with latest in february 1st, 2021)
(selected php-fpm as default)
There is a bug in Virtualmin with PHP-FPM if you delete all the virtual servers. When you restart php-fpm (sudo systemctl stop php7.4-fpm.service and then sudo systemctl start php7.4-fpm.service) you will get the error:
Job for php7.4-fpm.service failed because the control process exited with error code.
See "systemctl status php7.4-fpm.service" and "journalctl -xe" for details.
After a lot of research and read the log, what is happening is that the last user.conf is not deleted from the /etc/php/7.4/fpm/pool.d/ folder. If I manually delete it (in my case is 1612737320410801.conf) I can start PHP-FPM again.
Also, it is not possible to add a new Virtual Server because php-fpm will not start it with this error.
[How to reproduce this bug]
Create some virtual servers - it doesn’t matter how many - and then delete them one by one. After you delete the last one everything will still okay.
But if you try to create a new Virtual Server, PHP-FPM will output the above error message (because Virtualmin script will restart php-fpm service).
Hope this can help other people.