Offline errors in Thunderbird 31.2.0

I’ve received a few dozen error reports about error messages saying gContactSync can’t sync or authenticate with offline.  Most logs are from TB 31.2.0 but that may just be a coincidence.

I haven’t been able to recreate the issue yet so I would really appreciate the following information from anyone who has seen this error message:

  1. Disable any security software you have (Internet Security Suite, firewall, antivirus, etc.).  Kaspersky Internet Security is known to cause this issue, so disable it and try again.  If that works, make Mozilla Thunderbird a Trusted Application:
  2. Go to the Menu -> File -> Offline and verify Work Offline is not checked
  3. Disable all other add-ons and restart Thunderbird.  Lightning + the Google Calendar Provider add-on have caused this issue in the past.
  4. Go to the Google Security page and verify that Access for Less Secure Apps is set to Enable
  5. Edit: Thanks to Julie from the comments: “So I went to Tools>Options>Network&DiskSpace>Connection/Settings and Selected “No Proxy”. Restarted Thunderbird, that message was gone, and now the gContactSync works.”
  6. Try downloading an old version of Thunderbird to see if that works.

If none of the above helps, please send me the following debug information:

  • Go to Menu -> Tools -> Error Console and paste the following then hit Evaluate.  Let me know what pops up:
    function reqLoaded() {if(this.readyState == 4){alert(this.status);}}var req=new XMLHttpRequest();"GET", "", true);req.onreadystatechange=reqLoaded;req.send();
  • Turn on verbose logging and send me the log if it happens again (the third bullet shows how to find the log file location).
  • Send me your prefs.js file (this contains all of your settings so I can look for something that is common between all affected users):
    1. View the gContactSync log file
    2. At the top it shows your Thunderbird profile folder location:
       * Log location:     C:\Users\Josh\AppData\Roaming\Thunderbird\Profiles\31fopnzq.default\gcontactsync\gcontactsync_log.txt
    3. Open the directory that contains the gcontactsync folder (C:\Users\Josh\AppData\Roaming\Thunderbird\Profiles\31fopnzq.default in my case)
    4. E-mail me the prefs.js file in this directory
  • If you know how to use Wireshark, a trace while trying to synchronize would be extremely helpful.


  1. #1 by Maarten on December 22, 2014 - 10:00 AM

    I had this issue until I added a second account. This was the same (and my only) Google account that was already there (personal adressbook).
    Now all synced well. After this I deleted the account I added to make syncing possible and gContactSync kept syncing perfectly. 🙂

  2. #2 by Julie Raines on February 22, 2015 - 3:22 PM

    Same offline errors as described –
    Did initial 4 steps, but step 5 made me nervous, so I didn’t do that step.
    Pasted the text in the error console, and the answer was 0
    Where would I send the files?

  3. #3 by Julie Raines on February 23, 2015 - 11:41 AM

    Update – I tried going all the way back to Thunderbird version 31.0. This did not solve the problem. any help would be appreciated.

  4. #4 by Julie Raines on February 24, 2015 - 10:57 AM

    Update – I fixed it! I noticed that in addition to the problems I was experiencing with this add-on, I was also experiencing another problem with Tools>Add-ons>Get Addons where I was receiving the message “Secure connection failed – uses an invalid security certificate…”
    I then remembered that I fixed a similar problem in Firefox by changing the Options setting to No Proxy.
    So I went to Tools>Options>Network&DiskSpace>Connection/Settings and Selected “No Proxy”. Restarted Thunderbird, that message was gone, and now the gContactSync works. Hope this helps someone else!

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