Lightning Aurora, Nightly and Earlybird. Rated 5 out of 5 stars
It's quite apparent that the Lightning team is not keeping up to date with Thunderbird Aurora, Nightly and Early bird, as the versions posted here, do not work!!
I used to test TB 15.0a2 and 16.0a1 and while Lightning did work at one time, it's no longer compatible!
The last update for Lightning 1.7a2 was May 14, 2012 and no longer works with TB 15.0a2.
The last update for Lightning 1.8a1 was May 10, 2012 and does not work with TB 16.0a1.
As per Philipp Kewisch's reply, the problems with Lightning updates have now been fixed and the updates can now be installed.
Understandably, there were problems, as with any software, so it's good to know that the Developers have worked very hard to resolve the issues.
Now, back to testing, TB Earlybird!
Many thanks for a prompt reply!
I'm sorry for this, but we are working on it as fast as possible. I know its taking ages, but there were really a lot of problems lately, some of them not within our reach. Please see our blog for details: https://blog.mozilla.com/calendar/
Update: This has been fixed now, nightly builds are back!