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LCE
Principal II
March 26, 2026
Question

CubeMX2: error when downloading packs

  • March 26, 2026
  • 3 replies
  • 480 views

Heyho,

wanted to check if C5 might be good for next project and have a first look at MX2.

Installed it, started project with C562 / Nucleo - and nothing happens, except for a short error message in the bottom right corner of the window: "error when downloading packs" ( + some file name).

Further info:

- Windows 11

- started MX2 first as normal user, then as admin, same behaviour

- all other STM32 tools running fine (MX1, IDE, Prog)

3 replies

LCE
LCEAuthor
Principal II
March 26, 2026

Tried to install now via the "Pack manager", now some more error info:

Error_Pack-manager.png

ST Employee
March 27, 2026

Hi @LCE,

it looks like STM32CubeMX2 cannot validate the HTTPS certificate when downloading packs from
https://developer.st.com/st-pack-server/ ....
This is typically related to network / proxy / corporate security settings:

Could you please share a bit more about your setup?
– Are you working on a corporate network and/or connected through a VPN?
– Are you using an HTTP/HTTPS proxy (company proxy or similar)?

* If you temporarily try from another network (e.g. home / mobile hotspot, without VPN),
do the pack downloads work?

* Do you have any corporate inspection tools / antivirus web protection enabled that might intercept HTTPS traffic?
If yes, can you temporarily disable them or add an exception for developer.st.com and try again?

*Can you open this URL in a browser on the same PC?
https://developer.st.com/st-pack-server/api/v1/pack/STMicroelectronics.nucleo-c562re_hw-board.2.0.0.pack 
If the browser also reports a certificate issue.


LCE
LCEAuthor
Principal II
March 27, 2026

– Are you working on a corporate network and/or connected through a VPN?

> – Are you using an HTTP/HTTPS proxy (company proxy or similar)?

Absolutely! And we have some strong policies.

But I usually do not have these problems.

 

> * If you temporarily try from another network (e.g. home / mobile hotspot, without VPN),
> do the pack downloads work?

Not possible, working from home office.

 

> * Do you have any corporate inspection tools / antivirus web protection enabled that might intercept HTTPS
> traffic?
> If yes, can you temporarily disable them or add an exception for developer.st.com and try again?

I'll try - but probably have to contact out IT department - and they don't like these exceptions...

 

> Can you open this URL in a browser on the same PC?
> https://developer.st.com/st-pack-server/api/v1/pack/STMicroelectronics.nucleo-c562re_hw-board.2.0.0.pack 
> If the browser also reports a certificate issue.

This works -  no complaining from browser (MS Edge) or VPN / Security stuff.

ST Employee
March 27, 2026

Hi @LCE 
Thanks for this clarification 

In this case, what you need is to configure a proxy or a certificate to be able to access the servers and download packages.

  • Get your certificate from your company IT or company portal.
  • Place it under C:\certificate, for example.
  • Add the Windows environment variable NODE_EXTRA_CA_CERTS with the path to this certificate file. (Make sure that the path has no quotes.)

env-variable.png

  • Finally, restart STM32CubeMX2.

You can also refer to this article for more details on: How to configure the proxy or certificate 

LCE
LCEAuthor
Principal II
March 30, 2026

Thanks for the reply.

 @Oussama_TROUDI  :

(why) has this been changed compared to the old CubeMX ?

CubeMX 1 does not have any problem downloading stuff here.

ST Employee
March 30, 2026

HI @LCE 

Nothing has really changed compared to STM32CubeMX.
STM32CubeMX was working in the same way and also needed a proxy/certificate to be configured in order to access the servers and download packages.