Teams not connecting with ERR_CERT_AUTHORITY_INVALID

Daniel 116 Reputation points


I'm using the Teams Client for Linux on a Ubuntu 18.04 LTS behind a corporate proxy.

This is what I get, when trying to login:

Failed to load: https://

I guess that this has something to do with the redirect to the corporate login page and the certificate that is used there. Any idea how to check the cert store of the teams client? Or how to fix this behaviour?


Microsoft Teams
Microsoft Teams
A Microsoft customizable chat-based workspace.
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Skype for Business Linux
Skype for Business Linux
Skype for Business: A Microsoft communications service that provides communications capabilities across presence, instant messaging, audio/video calling, and an online meeting experience that includes audio, video, and web conferencing.Linux: A family of open-source Unix-like operating systems.
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  1. Daniel 116 Reputation points

    Finally I got it running with adding our root CA cert with certutil

    certutil -A -n "ROOT-CA" -t "TCu,Cu,Tu" -i /usr/share/ca-certificates/ROOT-CA.crt -d sql:/home/${USER}/.pki/nssdb

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  1. JimmyYang-MSFT 50,446 Reputation points Microsoft Vendor

    Hi Daniel!
    Does anyone else have the same issue?
    In my experience, Teams for Linux client don't need to install certificate. In our test environment(Ubuntu 18.04), we installed the Teams for Linux and didn't install certificate. It works well. So we think this issue may related to corporate proxy certificate. We recommend you check if your corporate certificate is trusted or expired. For more details about this issue, you can refer to:

  2. Juhász István 1 Reputation point


    I'm working on a linux (ubuntu) machine. I have the exact same problem.

    I've already tried the followings:
    -We have MITM decrypt for https, so internal ca have been added to the cert store of the system.
    -With wget I checked that the url from the log works well.

    Error log of Teams:
    Mon Nov 23 2020 11:24:56 GMT+0100 (Central European Standard Time) <7906> -- event -- name: desktop_navigation_provisional_load_failed, errorCode: -202, errorUrl:, message: ERR_CERT_AUTHORITY_INVALID, vdiMode: 0, eventpdclevel: 3,
    Mon Nov 23 2020 11:24:56 GMT+0100 (Central European Standard Time) <7906> -- error -- Page failed to load with error code -202: ERR_CERT_AUTHORITY_INVALID:
    Mon Nov 23 2020 11:24:56 GMT+0100 (Central European Standard Time) <7906> -- warning -- Page failed to load with unhandled error code -202: ERR_CERT_AUTHORITY_INVALID:

    Wget output:
    juhaszis@DSOL-0012N:~$ wget -d
    DEBUG output created by Wget 1.20.3 on linux-gnu.

    Reading HSTS entries from /home/juhaszis/.wget-hsts
    URI encoding = ‘UTF-8’
    Converted file name 'index.html' (UTF-8) -> 'index.html' (UTF-8)
    --2020-11-23 11:26:29--
    Resolving (, 2620:1ec:42::132
    Caching => 2620:1ec:42::132
    Connecting to (||:443... connected.
    Created socket 3.
    Releasing 0x000055b94eb4f6f0 (new refcount 1).
    Initiating SSL handshake.
    Handshake successful; connected socket 3 to SSL handle 0x000055b94eb4f820
    issuer: CN=NL_InternalCA,O=Netlock Kft.,L=Budapest,ST=Budapest,C=hu
    X509 certificate successfully verified and matches host

    ---request begin---
    GET / HTTP/1.1

    Does teams use same internal cert store instead of the OS store on linux?
    Do you have some workaround?


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