How to debug problemm mqtt-zabbix witch send data mqtt-zabbix.py:
send_to_zabbix([Metric(KEYHOST,
KeyMap.mapdict[msg.topic],
msg.payload)],
ZBXSERVER,
ZBXPORT)
call metod from zbxsend.py :
send_to_zabbix([Metric('localhost', 'bucks_earned', 99999)], 'localhost', 10051)

in log file mqtt-zabbix have failed: 1:
Sending localhost devices/6lowpan/aaaa::212:4b00:79e:b687/lps331/measure 995 to Zabbix key mqtt.external.pressure 127.0.0.1 10051
2016-09-29 11:53:03,692 Got response from Zabbix:

{u'info': u'processed: 0; failed: 1; total: 1; seconds spent: 0.000006', u'response': u'success'}

2016-09-29 11:53:03,692 processed: 0; failed: 1; total: 1; seconds spent: 0.000006

manual send OK:
zabbix_sender -vv -z localhost -p 10051 -s "10.5.10.197" -k "mqtt.external.pressure" -o "995.0"
zabbix_sender [11893]: DEBUG: answer [

{"response":"success","info":"processed: 1; failed: 0; total: 1; seconds spent: 0.000035"}

]
info from server: "processed: 1; failed: 0; total: 1; seconds spent: 0.000035"
sent: 1; skipped: 0; total: 1