ElasticSearch 5.6 cannot start on Mac OS

Question

I can\'t start ElasticSearch 5.6 server on Mac after installing it with Brew. Get this error:

$ /usr/local/opt/elasticsearch@5.6/bin/elasticsearch
Exception in t         


        

Answer 1

The server is most probably attempting to read a newer index (org.apache.lucene.index.IndexFormatTooNewException).

Most probably the only way is to get rid of it completely with:

sudo rm -rf  /usr/local/var/lib/elasticsearch

Please double check the index and make sure you don't need the old 6.* index anymore, because you're obviously going to lose it.