Just encountered a confusing systemd error when I tried to restart a service who's unit file was recently changed:
[nick@onebox ~]$ systemctl status stats_collector.service stats_collector.service - Stats Collector Loaded: error (Reason: Bad message) Active: failed (Result: resources) since Thu 2013-08-29 18:29:52 UTC; 1min 30s ago Main PID: 16920 (code=exited, status=1/FAILURE)
Turns out, an erroneous newline was added, adding unknown directive to the unit file. So, 'Bad message' seems to be roughly the equivalent of a 'syntax error'. Bad message! Bad!