I having difficulty setting up pidgin to work with my company's microsoft 365's communicator lync 2013 (not 2010) account.

I either receive a message stating authentication failed, or Incompatible authentication scheme chosen: NTLM depending upon the user agent values used from this wiki

It appears that both the user agent values that start with UCCAPI provide authentication failed error, which I'm guessing is "closer" to the solution.

I have triple checked that the password is correct.

Below are some images of my settings (I have changed the company name to "company" for annonymity.

enter image description here enter image description here

I am running pidgin with a script in order to fix a write error issue:

pidgin -d

I am also using the latest version of SIPE (1.10.1) by using this ppa: https://launchpad.net/~aavelar/+archive/ppa

What settings do I need to change/add to get it to work?

  • 3
    Did you try using the full user agent string? UCCAPI/15.0.4420.1017 OC/15.0.4420.1017 (Microsoft Lync)
    – mason81
    Oct 30, 2013 at 12:58
  • 1
    My company switched over to use Office 365 and I needed to adjust some settings, I found the information here to be helpful: vincentpassaro.com/2013/02/01/…
    – mason81
    Mar 18, 2014 at 15:15
  • Did you ever get your contact names to display in Pidgin running on Windows ? I have the same issue.
    – user339593
    Oct 17, 2014 at 11:52
  • @Paulreg Names only appear for me when I have manually added them to lync. It's a major pain and would love a solution to that. Oct 17, 2014 at 14:51
  • The advice given on this page used to work great, but stopped working during the summer. I now get "Failed to authenticate to server" or "Incompatible authentication scheme chosen" depending on the settings I chose, but nothing works. Does anyone have any insight? I'd offer a bounty, but I don't have enough rep :-( Sep 4, 2015 at 8:02

6 Answers 6


I was able to get this working on ubuntu 13.04 (question asked on ubuntu 12.04). Here are a few pointers:

Use the full user agent string as @mason81 pointed out:

UCCAPI/15.0.4420.1017 OC/15.0.4420.1017 (Microsoft Lync)

I did not need to use a startup script to solve any write errors. e.g.

pidgin -d

That linked repo was pointless on this distro, don't use it. It appears that on Ubuntu 13.04 you will install pidgin-sipe 1.13.3-1 by default which is an even more up-to-date version.

It appears that the pidgin/sipe setup I have installed here has a third authentication type for TLS as seen in this picture which is what I needed. enter image description here

For reference, here are my connection settings that are working: enter image description here enter image description here

The other tabs are the defaults


To get this working in ubuntu 14.04, do exactly the same, but untick the single sign on!

  • 1
    Thanks for the update for 14.04 -- I finally got around to upgrading and then couldn't connect to lync and it was driving me crazy!
    – mason81
    Aug 25, 2014 at 13:58
  • This configuration works on the Windows version of the Pidgin client too. I didn't tick single sign-on, not sure if it makes any difference. Thanks. Dec 8, 2014 at 16:42
  • Confirmed this also works on 16.04. (With single sign-on unchecked.)
    – Tass
    Apr 3, 2017 at 14:25

I manged to get this working on Ubuntu 12.04 with the pidgin (2.10.3) and pidgin-sipe (1.11.2-1ubuntu1) installed from the default precise/universe repo. We are using Lync2013 also.

I did use an environment variable to run pidgin. Without this pidgin would fail every time with a 'Read failed'. This was configured in /home/myuser/.profile by appending:


Check here for more information about why this variable is needed for sipe.

The sipe settings were as follows

'Basic' tab:

  • Username: my email as used within the company (e.g [email protected])
  • Login: company logon domain\username (e.g COMPANY\john.smith)

Advanced tab:

  • Connections type: Auto
  • User Agent: UCCAPI/15.0.4420.1017 OC/15.0.4420.1017 (Microsoft Lync)
  • Use Single Sign-on: [ticked]

All other fields in Advanced were blank. I had no proxy configured.


This is what is currently working for me. I have an Office365 account.


Username: [email protected]

Login: [email protected]

Password: *****

[CHECK]Remember password

Local alias: My Name


Server[:Port]: BLANK

Connection type: SSL/TLS

User Agent: UCCAPI/15.0.4481.1000 OC/15.0.4481.1000 (Microsoft Lync)

Authentication scheme: TLS-DSK

[UNCHECK]Use Single Sign-On

The rest is blank


Took a while to sort out, but this article did help quite a bit. Things to know:

  1. User agent is different depending on version of Lync your company has running and it's patch level. I found my agent by finding someone on MS Lync (not linux) and looking in a uccapilog file (it's under the Lync\Tracing directory) searching for UCCAPI.
  2. I at least had to find the server, and had to use the direct IP instead of DNS, found that info in the same file as above.
  3. The authentication scheme is dependent on your company's choices when they setup Lync, mine was NTLM.
  4. I did not use Single-Sign-on as my workstation login is not my domain login.
  • 1
    To which “article” are you referring? May 1, 2015 at 15:01
  • @DavidFoerster it's definitely unclear but he may be referring to this Q & A?
    – Elder Geek
    May 1, 2015 at 16:09

If you have you got MultiFactorAuthentication enabled you will need to give "app password" in the basic tab and email login and email password in the advanced tab.


For reference: I first got Pidgin/SIPE working on Ubuntu following Programster's instructions. I then tried on Windows and it failed with an error message

Web ticket request to https://webpoolams0e08.infra.lync.com:443/CertProv/CertProvisioningService.svc failed

Unticking SSO, again according to Programster's, instructions solved that. Only problem now is that no names are visible for my Lync contacts. If I mouse over they a "tool tip" with the name appear but the name remain invisible when the mouse is not there.

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