@skalliger is likely on target with the comment about Splunk versions. Having just went through this myself, I'm going to say it's likely the Splunk version and Python 3 that is biting you. See if you have log entries that look like this:
"ImportError: No module named 'ConfigParser'"
I'm going to guess that you do.
Since you're testing and not version dependent, just install Splunk 7.3.4 and you should be good to go.
https://www.splunk.com/page/previous_releases
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