Lightning 1.0 Beta 2 Release Candidate 2 is available

With some delay, we are happy to announce Lightning 1.0b2 release candidate 2. With this release we’ve mainly fixed bug bug 570464, but also made sure we were using the right localization files.

Please re-test if Lightning works in your language! Back with rc1, I accidentally used the newest version of the localization files, but not the version that the localizers suggested. I did notice some further change to the localization files, so it would be great if you could double check.

Candidate builds for Lightning 1.0 beta2 in 33 languages are available as of now for:

A corresponding build of the Provider for Google Calendar is also available at those locations.

Note you will need Thunderbird 3.1 (or a release candidate thereof) to try it out. You are encouraged to back up your profile before upgrading. To install these builds in Thunderbird 3.1, please follow these steps:

  1. Download the build for your operating system to a folder on your hard disk.
    NOTE:Please make sure, that you right-click on the links above and choose “Save Link as…”. Otherwise Firefox will try to install Lightning and you will get an error message like “Lightning 1.0b2 could not be installed because it is not compatible with Firefox.”
  2. Open Thunderbird, then open its add-on manager via Tools –> Add-ons (or the corresponding entry in your language)
  3. Click on the “Install…” button on the lower left and navigate for the lightning.xpi file that you just downloaded.
  4. Restart Thunderbird after the add-on installation has been performed. Voila!

We will be releasing the final version of Lightning together with Thunderbird 3.1. There is not much time left before this release, so I encourage you to do the testing rather sooner than later.

Please tell us what you think of these candidate builds and file bugs in Bugzilla as you go. We are really looking forward to this release, I hope you are too!


  1. Will Lightning 1.0 beta2 be also compatible with TB 3.0.x ?

  2. LInda Skilbeck

    I followed tjhe instructions above aboujt right clicking and got the error message. I dont think the the link for windows is working