I was having a similar error on your version before upgrading.
Here's what I did;
If this returns PID's with zmlog referenced, then;
Code:
kill *PID_zmlog_Number_Here* ; kill *PID_zmlog_Number_Here*
then again;
if that's clear (besides example; 13121 pts/2 S+ 0:00 grep zmlog)
then;
Code:
zmlogswatchctl start
zmcontrol status
Log-in to the web interface and logger should be active again.