We are also facing the same issue after installing ssl on hostname the pure-ftpd stop responding after restart on checking up the status it gives below result
[root@host custombuild]# systemctl status pure-ftpd
● pure-ftpd.service - Pure-FTPd FTP server
Loaded: loaded (/etc/systemd/system/pure-ftpd.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Sat 2020-08-15 14:19:06 IST; 28s ago
Process: 116312 ExecStart=/usr/sbin/pure-ftpd /etc/pure-ftpd.conf (code=exited, status=0/SUCCESS)
Main PID: 116313 (code=exited, status=252)
Aug 15 14:19:06 hostname.com systemd[1]: Starting Pure-FTPd FTP server...
Aug 15 14:19:06 hostname.com systemd[1]: Started Pure-FTPd FTP server.
Aug 15 14:19:06 hostname.com pure-ftpd[116313]: (?@?) [ERROR] Sorry, but that file doesn't exist: [/etc/pure-ftpd.pem]
Aug 15 14:19:06 hostname.com systemd[1]: pure-ftpd.service: main process exited, code=exited, status=252/n/a
Aug 15 14:19:06 hostname.com systemd[1]: Unit pure-ftpd.service entered failed state.
Can anyone help regarding this it will very grateful to us