Rebalance buckets_cleanup_failed

I am trying to add a node to my cluster and rebalance fails with following log entries ( is the source node that I am trying to replicate to a new node in a 2-node cluster):

Failed to cleanup old buckets on node ‘ns_1@’: {error,eacces}

Rebalance exited with reason {buckets_cleanup_failed,[‘ns_1@’]}

Unable to delete bucket database directory config

Deleting old data files of bucket “config”

Starting rebalance, KeepNodes = [‘ns_1@’,‘ns_1@’], EjectNodes = , Failed over and being ejected nodes = ; no delta recovery nodes