Why is SSL on Universal Forwarder failing with error "WARN SSLCommon - Received fatal SSL3 alert"?

Hi, I just followed the answer in the below post to configure SSL between my UF and the indexer: answers.splunk.com/answers/211383/why-am-i-getting-errors-with-my-ssl-configuration.html?utm_source=typeahead&utm_medium=newquestion&utm_campaign=no_votes_sort_relev Im seeing the following error in the splunkd.log when i restart splunkd: 07-06-2017 16:08:22.151 +0100 ERROR X509Verify - X509 certificate (O=SplunkUser,CN=SplunkCA,O=SplunkInc,L=SanFrancisco,ST=CA,C=US) failed validation; error=19, reason="self signed certificate in certificate chain" 07-06-2017 16:08:22.151 +0100 WARN SSLCommon - Received fatal SSL3 alert. ssl_state='SSLv3 read server certificate B', alert_description='unknown CA'. 07-06-2017 16:08:22.151 +0100 ERROR TcpOutputFd - Connection to host=xxx.xxx.xxx.xxx:9778 failed. sock_error = 0. SSL Error = error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed 07-06-2017 16:08:22.193 +0100 ERROR X509Verify - X509 certificate (O=SplunkUser,CN=SplunkCA,O=SplunkInc,L=SanFrancisco,ST=CA,C=US) failed validation; error=19, reason="self signed certificate in certificate chain" Any pointers on this would be great, i've tried using signed certs and was seeing the same error.