# Can't generate the certs.ar from certs-from-mozilla.py

**URL:** <https://community.hivemq.com/t/cant-generate-the-certs-ar-from-certs-from-mozilla-py/1230>\
**Category:** HiveMQ Cloud\
**Created:** [May 23, 2022, 8:32pm UTC](https://community.hivemq.com/t/cant-generate-the-certs-ar-from-certs-from-mozilla-py/1230 "2022-05-23T20:32:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![aekzitouni](https://avatars.discourse-cdn.com/v4/letter/a/71c47a/32.png) [@aekzitouni](https://community.hivemq.com/u/aekzitouni)\
**Post date:** [May 23, 2022, 8:32pm UTC](https://community.hivemq.com/t/cant-generate-the-certs-ar-from-certs-from-mozilla-py/1230/1 "2022-05-23T20:32:00Z")

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Hello there,

I am really new in MQTT. I am trying to connect my “nodemcu/esp8266” device to the cloud using free HiveMQ. I followed with success all required steps:

- Install Arduino IDE
- PubSubClient library
- NTPClient library
- LittleFS Filesystem Uploader  
But at the “Upload certificates to the board” step I am facing an issue: The “certs-from-mozilla.py” does not compile (or run) to generate the “certs.ar” required file. I am using Visual Studio Code on Windows 10 for this purpose. My problem is with the “urllib2” in line 21 and the “StringIO” in line 23 which can not be resolved.

Is there any solution for this problem.

Kind regards

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**Author:** ![gendiaaa](https://avatars.discourse-cdn.com/v4/letter/g/a8b319/32.png) [@gendiaaa](https://community.hivemq.com/u/gendiaaa)\
**Post date:** [July 30, 2022, 4:35am UTC](https://community.hivemq.com/t/cant-generate-the-certs-ar-from-certs-from-mozilla-py/1230/2 "2022-07-30T04:35:20Z")

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do not use visual studio and use python or you have to change the import in the code