What means the message "Downlink transmission failed with result UNKNOWN_ERROR"?

Hello everyone

Im getting the message “Downlink transmission failed with result UNKNOWN_ERROR” after to get an forward uplink data message, this event is always, I’m not scheduling any downlink to transmit

About lora configurations:
Gateway: Tektelic kona Enterprise
LoraWAN version: 1.0.3
Plan Frequency: Sub-band 1

I share you this image

can you help me to understand what means this message and whi I get it.

Warmest regards.

  • Angel_BN

Details! Don’t expect the volunteers to start playing a game of 20 questions before they can step in and help. Can you post full message and associated info as well……

Hi Jeff

Thanks for your early answer, so sorry, it’s my firt time posting in this forum

I hope you can help me with the doubt

I doubt he can help with your doubt as you’ve not actually told us any details like he asked.

“My car won’t reverse” - think what details your mechanic would ask if you said that.

Now do the same thing, bearing in mind that none of the mechanics are paid so you need to do the running.

Please share new information in a new message, not by editing the previous one. We don’t have time to scroll back to old messages to check if those suddenly changed and contain additional information.

Additional questions:

  • do you own a gateway that receives the uplinks? If so, is there anything in the gateway console?
  • for the failure message, click on it and copy and paste the json into your reply, use the formatting tools on top of the edit box to format the json so it is readable.

Yea the gateway it’s mine

I got this on the console showing the pkt_forwarder.log

it sometimes appears after to send the uplink

here is the json from the gateway console:


and this is the Json from the TTN “live data”

  "name": "ns.down.transmission.fail",
  "time": "2023-12-01T23:28:42.712849523Z",
  "identifiers": [
      "device_ids": {
        "device_id": "desarrollo-nodo-eqysr000007",
        "application_ids": {
          "application_id": "pdxl-01"
        "dev_eui": "0080E10A00000007",
        "join_eui": "0101010101010101",
        "dev_addr": "260CA0A6"
  "data": {
    "@type": "type.googleapis.com/ttn.lorawan.v3.ErrorDetails",
    "namespace": "pkg/networkserver",
    "name": "transmission",
    "message_format": "downlink transmission failed with result `{result}`",
    "attributes": {
      "result": "UNKNOWN_ERROR"
    "correlation_id": "32eebaaa260d4d3a8837cb67dbd1c0c9",
    "code": 2
  "correlation_ids": [
  "origin": "ip-10-101-7-99.us-west-1.compute.internal",

Do you know if there are a list about the resutls from the message “downlink transmission failed with result”?
I have seen in others post of this forum that this massage returns diferents errors like: UNKNOWN_ERROR, COLLISION_BEACON and TOO_ERALY.

Thank you

Have you found the article in the documentation that matches that message?

tell us what node you are using and how it is setup

stack you are using

what you are doing

are you sending downlinks

remember there are 1500000 different nodes on the network and 1000 of variants we cant guess what you are busy doing

ok here we go with the firts guess

100% guess you sent a unknow error to the node
as this equates to the information you supplied :wink:

please be clear as to what you are doing


About the node, I’m using an embeded node that I´m developing whit RAK3172 module
I used LoRaWAN stack from STMicrocontrollers, I mean LoRaWAN SDK for STM32

There are not any downlink scheduled for transmition and sometimes I got this erron when I send the uplink

I thing that I have the “TX power” parameter in the Gateway with a bad value becouse I got in log the message

WARNING: Requested TX power is not supported (26.000000dBm), actual power used: 24dBm