I just beta tested 43 tonight and the right version of Lightning came with it. I also reverted to 42 to check the upgrade to 43 and Lightning came through OK. Go figure.

Do you know how or why you came to be on the beta channel? You say you rely on your calendar, so it seems somewhat imprudent to be using a beta version.

I don't know how or why I got the "beta channel". This is the first time I noticed that... especially when it came up saying to expect "nightly" updates. That is one reason why I'd like to understand how to back out of this without losing everything. I don't see anywhere in the options to specify I want official ones.

I find it interesting that you got a compatible version of lightning. I have 4.4b2 which is disabled as it is not compatible with 43.0 of Thunderbird. Could not find one on the Lightning url that was.

Hmm, I get Lightning 4.8a1 with my nightly. Although that is following today's update.

However, the downgrade your looking for is as simple as downloading and installing the release version. getthunderbird.com

Thank you Matt!!!!!!!!! In my ignorance, I did not think it would be so easy. I now have 38.5 with Lightning 4.0.5 and my beloved calendar has returned. Have a good new year. You made mine!!!!

In a larger sense, note the reference to "beta channel" that is not explained anywhere in the TB documentation.

I remember somewhere being able to choose from stable, beta, nightly, and other release or update channels. Once a channel is selected, you are stuck with it until you can rediscover the magic dialog box for choosing channels.

I have searched for this hidden dialog box and cannot find it.

Why can't this be documented? Can anyone explain how to find it, please?

I was wondering why I went from version 38.7.2 to 45.1.0!! I got the message about being on the "DAILY" for NIGHTLY updates, AFTER THE UPDATE WAS DONE!!! Why am I on this NIGHTLY?? How can I get BACK to just getting WEEKLY updates that keep Bugging you for a few weeks, until the Next update????????

Thunderbird 45.1.0 is a Release and not a Nightly build. As you can see it is the current Release on on https://www.mozilla.org/thunderbird/

The message about Daily if you have the Start page still enabled was sent to the Tb 45.1.0 release users by mistake as it was intended for the Daily users only.

If your question is "how to switch from one automatic update distribution list to another", there are many incorrect answers posted on the Web. I believe the correct answer is this:

"Do a manual download of an update from the distribution list that you desire to be switched to. As soon as you install the update, you will be switched to that new list."

If this is incorrect, and you are certain it is incorrect, please post a correction here.

David Spector said

If your question is "how to switch from one automatic update distribution list to another", there are many incorrect answers posted on the Web. I believe the correct answer is this: "Do a manual download of an update from the distribution list that you desire to be switched to. As soon as you install the update, you will be switched to that new list." If this is incorrect, and you are certain it is incorrect, please post a correction here.

Correct, but not relevant here me thinks.