Problem is here : https://community.cloudera.com/t5/Storage-Random-Access-HDFS/HMaster-not-starting-TableExistsException/td-p/11466

The solution:

First, perform

zookeeper-client -server ip port

on the zookeeper node. We get:

Then, perform

ls /

we get:

[zookeeper, yarn-leader-election, chronos, hbase]

Finally, perform

rmr /hbase

Done!