My sincere apologies for the slow reply; It was a national holiday in Korea, most people could not participate.
'Connection refused' error means that our application can not communicate with Druid.
metatron use the druid, but you seems to be not installed (or not running) it.
Please refer this link to install druid.
If you have any questions or need further information, please feel free to ask.
Thanks,
Alchan.