I have been receiving a ResponseNotReady - 500Internal Sever error from the point that Splunk has been upgraded to Splunk 6.
How can I resolve this issue?
Running Splunk on Windows? This error is likely due to Splunk being unable to talk to itself. It's a known issue with Windows, see:
This answer has the most detailed information, in terms of users' experience.
http://answers.splunk.com/answers/68368/splunk-web-throws-responsenotready-error