Can't start ElasticSearch on Mac

Did you have an older version (2.x or before) installed before? It sounds a lot like this PR to check that you're not using the old behavior when there was the node name in the path.

What I would do:

• If you don't need the data any more, just remove /usr/local/var/lib/elasticsearch/elasticsearch_nikitavlasenko and start fresh.
• If you need the data, you could either change path.data in your config or move the folder one level up (just like the log message says).

PS: I wouldn't use port 9300 for HTTP, because that's generally the port used for communication of the nodes in a cluster itself.

This was the result of a bug in the Homebrew formula for Elasticsearch. It was creating a directory with the node name which is no longer allowed for Elasticsearch.

The formula has been updated to remove node name from path.data and no longer create the invalid directory which should resolve this problem.