NodeMCU (ESP8266) upload error

Hi everyone.
I have been working fine with the NodeMCU board connected to an arduino to upload telemetry data to ubidots for several weeks.
Today I started to have problems.
At first I thought that the board was failing or something.
I connected it to my computer to debug it, and I got this message from the esp8266 when it tries to upload data:

01:18:54.698 -> Sending data…
01:18:55.346 -> [ERROR] Could not verify the remote secure server certificate, please make sure that you are using a secure network
01:18:55.448 -> Ok


I Will appreciate any help you can give me with this.

Greetings, the error that appears at your serial debugger means that the secure server certificate could not be authenticated, this sort of alert means that you cannot implement a secure TLS connection to Ubidots due to some sort of network security risk. I advise you to try on another network.

All the best

1 Like

Apparently I fixed it changing the method for uploading the data.

I was using HTTP to send the variables. I figured out that using MQTT I stop getting errors:


Greetings, just to clarify, the example that you have used do not ‘fix’ the issue as it is based on the PubSubclient library that implements a non-secure based socket connection and thus of that a remote server certificate authentication is not needed. Keep in mind that this is not an ‘error’, it is an issue related with your network security. The MQTT example does not validate remote certificates in order to make the code easier to understand, but it does not mean that you are not actually exposed to the ‘man in the middle’ security risk that you were obtaining using HTTP. If you are planning to deploy your solution in a commercial/production environment, we highly ask to our users to implement a secure TLS connection.

All the best

1 Like