When I updated Dovecot to it's newest version today I got the following error at the end:

Restarting dovecot.
Stopping dovecot: cat: /var/run/dovecot/master.pid: No such file or directory
usage: kill [-s signal_name] pid ...
       kill -l [exit_status]
       kill -signal_name pid ...
       kill -signal_number pid ...
                [ FAILED ]
Starting dovecot:               [ OK ]
Fatal: Dovecot is already running with PID 90184 (read from /var/run/dovecot/master.pid)
So... first it says that it does not find the file, then it is already there... Anyway after that I restarted Dovecot and everything is OK:

root@srv2:/usr/local/directadmin/custombuild # /usr/local/etc/rc.d/dovecot restart
Stopping dovecot:               [ OK ]
Starting dovecot:               [ OK ]
FreeBSD 11.3 here.