Received fatal alert: bad_certificate

We are using logstash version 2.3.4 . A cluster of logstash instances gets events from log-courier, filebeat and lumberjack input plugins. Here are the versions of each input plugin.

log-courier 1.9.0
filebeat 2.29
lumberjack 2.0.7

I saw below errors (in logstash.log) when I started to rollout couple of changes to logstash instance to enable JMX Metrics collection. I verified the SSL Cert (we use self signed certs) and no issue with the certificate. Below error message is not helping me much to resolve. Appreciate your inputs. Let me know if you need additional details.

{:timestamp=>"2016-10-18T22:07:44.820000+0000", :message=>"Connection failed to initialise", :error=>"Received fatal alert: bad_certificate", :peer=>"xx.xx.xx.xx:60749", :level=>:warn}
{:timestamp=>"2016-10-18T22:07:45.188000+0000", :message=>"Connection failed to initialise", :error=>"Received fatal alert: bad_certificate", :peer=>"xx.xxx.xx.xxx:2960", :level=>:warn}
{:timestamp=>"2016-10-18T22:07:50.701000+0000", :message=>"Connection failed to initialise", :error=>"Received fatal alert: bad_certificate", :peer=>"xx.xxx.xxx.xxx:60758", :level=>:warn}