Undefined method for "check_last_wal_received"

[mcbuehler]

When I call
/check-barman.rb -a last_wal -s <HOST> -w 300 -c 600
I get this error:
.../check-barman.rb:95:in check_last_wal_received': undefined method created' for nil:NilClass (NoMethodError)

Apparently the object latest.wal_files.last does not exist.

[pavelliano]

Is your barman home directory located in default (/var/lib/barman) or elsewhere?
If not consider using -h parameter for setting your home directory location.