Error: tx payload unmarshal error


I get a strange error randomly in the lora app server logs. I am trying to send the same message to multiple end-devices (i post X times the same message in the MQTT broker with different targets), but i get this error only once and the message is received for all the other devices. Here is the message:

time="2018-08-27T00:28:31Z" level=info msg="handler/mqtt: data-down payload received" topic="application/1/node/000000047415004c/tx"
time="2018-08-27T00:28:31Z" level=info msg="device-queue mapping created" dev_eui=000000047415004c f_cnt=18 id=361 reference=94990a95-cf60-4230-810f-a22caedf2aac
time="2018-08-27T00:28:31Z" level=info msg="downlink device-queue item handled" confirmed=true dev_eui=000000047415004c f_cnt=18 reference=94990a95-cf60-4230-810f-a22caedf2aac
time="2018-08-27T00:28:47Z" level=info msg="device-queue mapping deleted" id=361
time="2018-08-27T00:28:47Z" level=info msg="downlink device-queue item acknowledged" dev_eui=000000047415004c
time="2018-08-27T00:28:47Z" level=info msg="handler/mqtt: publishing ack notification" topic="application/1/node/000000047415004c/ack"
time="2018-08-27T00:28:48Z" level=info msg="handler/mqtt: data-down payload received" topic="application/1/node/000000047415004c/tx"
time="2018-08-27T00:28:48Z" level=error msg="handler/mqtt: tx payload unmarshal error: json: cannot unmarshal string into Go value of type handler.DataDownPayload" data_base64=IntcImNvbmZpcm1lZFwiOnRydWUsXCJkYXRhXCI6XCJFQUE9XCIsXCJmUG9ydFwiOjEwLFwicmVmZXJlbmNlXCI6XCI5NDk5MGE5NS1jZjYwLTQyMzAtODEwZi1hMjJjYWVkZjJhYWNcIn0i

I am using LoRa App Server 0.16.0, which I am just realizing writing this post is pretty old, so maybe this is an issue that has already been fixed.

Thanks for your help

We have a retry mechanism, that’s why we can see there are 2 messages being sent

My bad, i send an incorrect message when retrying… Sorry