Zabbix 3.0 or later agent does not stop on RHEL5 with init script if PidFile parameter contains \r in the end in zabbix_agentd.conf
# /etc/init.d/zabbix-agent stop Shutting down Zabbix agent: [FAILED]
The same problem was fixed on ZBX-9626, but the fix was for only 2.2 and 2.4. Same problem happens on 3.0 or later, only on init system.