Lightning 1.1.1 fixes a critical error on Windows XP

Due to a critical issue that some Windows XP users are experiencing, we have decided to release Lightning 1.1.1, an intermediate release compatible with Thunderbird 9/Seamonkey 2.6. We recommend all users to upgrade, especially those who cannot see their calendar data and are getting an error console message “Failed to load native module at path …calbasecomps.dll”.

You can get the builds on, as always.


  1. I just downloaded and tried to install, only to encounter “Not compatible with Thunderbird 3.1.17”. That version silently crept onto my system on or about 6 Jan 2012 and I’ve been without a calendar ever since. Is there an ETA for a compatible version?

  2. @Rich:
    Please use Lightning 1.0 beta 2, if you are still using Thunderbird 3.1.17. It is available at
    Newer versions of Lightning are only released for the current Thunderbird release at the time. You can find an overview of past and current releases of Lightning at
    Each entry there contains information on which Thunderbird release is suitable for each given Lightning release.

  3. I am running Thunderbird 9.0.1 and Lightning 1.1.1 on Windows 7 Home Premium, SP1. When I receive Outlook meeting invitations, they are displayed in a formatted box in the email, but there is no attachment shown, and the event is not placed in the calendar. I viewed the same email in Windows Live Mail, which showed it had an attachment “ATT000006.txt”. I saved it as “ATT000006.ics” and then was able to import it into Lightning. Is this a known issue, or is there something I need to do to enable scheduling of these meetings in my Lightning Calendar with Thunderbird?

  4. DISASTER! Thunderbird automatically updated to 11 with a very yucky new UI.

    Please, refer me to a TB version that has a compatible version of Lightning–I’m without a calendar.

    I tried rolling back to TB 10, but FF claims it’s incompatible with the TB10’s version of Lightning

    I’ve rolled TB back to 9.0, but can no longer find a compatible version of Lightning (supposedly Lightning 1.1.1 will work, but I can’t find a download site)

    Please, don’t suggest I download the latest versions of FF, TB and Lightning–I don’t have time to be a beta tester and Im tired of rolling back these dreadful quick releases

    Please–I need a calendar

    • Philipp Kewisch

      When you download Lightning, be sure to save it on your computer. If Firefox is saying its incompatible with Lightning, thats of course correct because Lightning doesn’t support Firefox. Be sure to use right click and save link as.

      You can get Lightning 1.1.1 and other older versions here.

      There is an extension to move the tabs to the bottom again, but be warned that its flaws nicely demonstrate why Thunderbird chose not to allow easy switching of the tab location.

      Maybe you’ll consider getting used to the new UI. After you use it for a while its really quite nice.