There is a calendar/lightning add-on offered in the ubuntu repository I understand you have to install that. Someone over an canonical apparently is rolling their own Thunderbird.

Matt, I am very grateful for your reply, however I have no idea about 'the ubuntu repository OR 'canonical'. If you could give me a bit more direct/links for further investigation on my part, that would be marvelous.

Previous updates of Thunderbird (linux OS, Mint 'flavor) have gone into effect with the calendar not displaying for a while (week-ish), but usually Lightning gets updated also. I really don't appreciate that Thunderbird releases an update that does NOT include the bundled calendar. Returning to an early Thunderbird version doesn't sound advisable so updating = get STUCK?!? Not cool at all.

Thunderbird releases an update the includes Lightning in the main distribution file. For some reason Canonical (that is the commercial company behind ubuntu) repackage Thunderbird to include the unity integration and remove the lightning add-on.

So if you want to complain, the ubuntu community is the place to start. https://packages.ubuntu.com/search?keywords=lightning

https://askubuntu.com/questions/307280/how-do-i-install-applications-in-ubuntu

But to your original question the theme used in mint leaves the second row of tabs in the preferences dialog looking like single words just hanging out under the top tab bar.

Much thanks Matt. I briefly looked at the links you wonderfully provided. Looks like Greek to me at this moment so will see if I can find a willing 'guide' to help me get this working for me on my computer. Thanks again!

Matt I do want to thank you for your assistance efforts, but after many and varied attempts to resolve this problem its still a BUST. I can't tell you how many forums and attempts I've read and tried to follow, but after following suggested instructions only to end up at missing parts needed to be found that those instructions included, now my computer seems MORE messed up than before. I don't know whether to scream, cry or laugh hysterically.

Its so uncool and trust breaking that Linux (of any flavor) seems to have broke Thunderbird's calendar before it (beta?) tested the update.

Just wanted to let others know that this is continuing to fail for me and I'm sure others too.

Can you give us a screenshot of the Edit|Preferences|Advanced pane? I think you may have overlooked Matt's advice pointing out the misleading rendering of tabs in Ubuntu.

The advice would be leading you to the Config Editor. I can't see how that can help with a missing Lightning. Can you provide a link to whatever site gave you that advice?

Zenos when I posted that my Advanced tab was missing, it was indeed not available at that time. Since then it has 'spontaneously' shown up.

Here's the link to advice re Advanced -> Config

https://support.mozilla.org/en-US/kb/calendar-updates-issues-thunderbird

You will have to scroll down to a few paragraphs to see this.

PS Zenos, I am using Linux Mint (17.3?) and not Ubuntu (though its possible that Mint is simply a built-off of Ubuntu). I have been using Thunderbird for so many years I can't even remember when I began using it thought I do remember I first had to use a cd to download it! talk about 'ancient' ;-)

Ah, thanks for the link. I hadn't seen that one.

It's part of a process intended to completely remove Lightning, so that it can be re-installed.

So, where are you now? You've been able to get into Edit|Preferences|Advanced and then presumably into the Config Editor?

Linux Mint is indeed built on the back of Ubuntu and shares much of its ecosystem.

Traditionally, many Linux distros have included Thunderbird as the default email client and distribute it via their software management tools (aptitude, synaptic, apt etc) from their repositories.

So it may be more appropriate for you to follow the Linux-specific advice given there.

Zenos when I did get into Advanced -> Config Editor and put the cut & paste supplied line from the instructions, that did NOT return the expected response. In fact the 'list' was blank. So I got to a dead end point and stopped there. My gut feeling is that I'm now caught in a Catch 22 - the Lightning Add On that was 'incompatible' is now gone and I can't get it add back because it is 'incompatible'.

Thanks for your efforts and I do have a post in both the Thunderbird and Linux Mint forums outlining my inability to make use of the instructions provided because those do NOT work for me.

as far as I can ascertain without installing mint you need to actually get the lightning XPI file from the repository. The package contains the words lightning and XPI in the Ubuntu repository. I assume you can find that ion your distros repository.

Or

Just install Thunderbird from the Linux package at getthunderbird.com. It contains the Lightning add-on that the Linux distributions leave out.