Another kind of data.path bug?

[LmYjQ]

kibana crashed suddenly in this afternoon

I found the log info:
Caused by: java.lang.IllegalStateException: detected index data in default.path.data [/var/lib/elasticsearch] where there should not be any; check the logs for details

I HAVE read the following blog: Multi data path bug in Elasticsearch 5.3.0 | Elastic Blog
But in my configuration, I have ONLY ONE path like this:

# ----------------------------------- Paths ------------------------------------
#
# Path to directory where to store the data (separate multiple locations by comma):
#
#path.data: /path/to/data
path.data: /data1/elasticsearch
#
# Path to log files:
#
#path.logs: /path/to/logs

And the response of following request

curl -XGET "http://localhost:9200/_nodes?pretty&filter_path=nodes.*.settings.path.data"
is
curl: (7) Failed to connect to localhost port 9200: Connection refused

instead of the json of paths.

How could I fix this? Thanks a lot

[LmYjQ]

UPDATE

I deleted the -E default.path.data=${DATA_DIR} in /usr/lib/systemd/system/elasticsearch.service

But another error came out

[security_exception] missing authentication token for REST request [/_nodes?filter_path=nodes.*.version%2Cnodes.*.http.publish_address%2Cnodes.*.ip], with { header={ WWW-Authenticate="Basic realm=\"security\" charset=\"UTF-8\"" } }