Barman issue

I am trying to do a poc on streaming backup and streaming wal method by making use of the pg_receivewal. I have already created a user with replication privilege the same is added in pg_hba. conf. And I am able to connect remotely using the user created.
But when I am running barman check pg
pg is the name given to the remote dB host. I am getting an error like this
EXCEPTION: LooseVersion instance has no attribute 'version'
Below I am pasting the conf files used:
[pg] 
conninfo
streaming_conninfo
streaming_archiver = on
slot_name = barman
backup_method = postgres 
path_prefix = Postgresql bin path
basebackups_directory
errors_directory
incoming_wals_directory
streaming_wals_directory

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I have already created the replication slots and started the pg_receivexlog remotely from the batman server. Was are streaming and is coming to the incoming_wals_directory 
Please note that there are 2 more servers configured with barman in this backup hosts which is working fine.. The o my difference theyvhave is that they are configured with backup_method = rsync.

I wanted to make use of pg_receivexlog instead of rsync. Hence this poc..

Please help. 

Thanks,

Roy