rsyslog - ID for group 'special' could not be found [try http://www.rsyslog.com/e/3003]

Issue

rsyslog is writing logs, but is not preserving the group and mode it is configured to use.

Incorrect permissions on badserver:

badserver$ ls -l /logs/badserver
drwxr-x--- 2 root root 4096 Apr 24 09:53 2015.03.23
drwxr-x--- 2 root root 4096 Apr 24 02:22 2015.03.24

Versus correct permissions seen here on goodserver:

goodserver$ ls -l /logs/goodserver
drwxr-s--- 2 root special 4096 Apr 23 18:01 2015.03.23
drwxr-s--- 2 root special 4096 Apr 24 04:01 2015.03.24

Checking /var/log/messages, the following logging is seen:

badserver$ cat /var/log/message* | grep rsyslogd
Mar 21 09:04:17 badserver rsyslogd-3003: ID for group 'special' could not be found [try http://www.rsyslog.com/e/3003 ]
Mar 21 09:04:17 badserver rsyslogd: the last error occured in /etc/rsyslog.d/custom.conf, line 9:"$DirGroup special"
Mar 21 09:04:17 badserver rsyslogd-3003: ID for group 'special' could not be found [try http://www.rsyslog.com/e/3003 ]
Mar 21 09:04:17 badserver rsyslogd: the last error occured in /etc/rsyslog.d/custom.conf, line 10:"$FileGroup special"
Mar 21 09:04:17 badserver rsyslogd: the last error occured in /etc/rsyslog.conf, line 31:"$IncludeConfig /etc/rsyslog.d/*.conf"
Mar 21 09:04:17 badserver rsyslogd-2124: CONFIG ERROR: could not interpret master config file '/etc/rsyslog.conf'. [try http://www.rsyslog.com/e/2124 ]