Addons are created by their author and are not created by Thunderbird. The author of the addon has sole responsibility to ensure their addons work with whatever version of Thunderbird.

Just like Anti-Virus products have the responsibility to keep up to date and ensure their products work with whatever they claim.

People who create addons rely on donations to afford them time to maintain their addon extensions. Their addons are frequently used by people who do not contribute, so they may be unable to afford to update.

So, you may discover any of the following may apply. The addon still works but needs updating as the auto update may have failed. The addon still works but has been replaced eg: 'ImportExportTools' has a new one called 'ImportExportTools NG'. Some addons are still being worked on to update the code and so may be available in the future. Some addons have not been updated for a long time, but continued to work until now. So the author may have stopped maintaining a while ago. Authors may have chosen to not upgrade because they do not have the time available or cannot afford the time or do not have the inclination to learn and apply the new coding which means totally rewriting the entire addon. Note some authors were maintaining several addons.

You would need to ask the specific author of the addon in question if they intend to update as it is not something Thunderbird can force. Lightning is the exception as it has been integrated.

Selection of addons already updated that do work in 68, but it is not a definitive list.

• ImportExportTools NG
• Remove Duplicates 1.6
• SmartTemplate4 2.7
• Mail Merge 6.1.0
• MRC Compose 2.0.2
• Signature Switch.
• XNote++
• Auto Address Cleaner T 1.0.7
• Manually sort folders 2.0.2
• QuickFolders (Tabbed Folders) 4.17.5
• Colored Folders 1.3.5
• Thunderbird Conversations 3.0.10
• Phoenity Buttons 3.5
• Profile Switcher 2.4
• Exquilla for Exchange
• Owl for Exchange
• gContactSync

I already understood all that, but you totally avoided answering my basic question, which is: WHY don't core developers take more care to AVOID breaking addons? This is just careless, thoughtless behavior. When a new release breaks a majority of addons without a very good reason, something is wrong. A lot of these addon developers are doing this for the benefit of the community, and by breaking so many addons, you are just pushing a lot of work down to these nice people. That is just rude and thoughtless. There needs to be a VERY GOOD reason, like a serious security hole, or (as happened a few years ago), a complete overhaul of the entire design of the product. Haven't seen anything about this release that suggests any such reason here. So my point remains, and you have not adequately addressed it. Thanks.

re :WHY don't core developers take more care to AVOID breaking addons? Thunderbird does not break the addon. The addon is not up to date. The addon is not keeping up to date with technology and security advancement.

So the user can choose to continue using out of date older Thunderbird versions and old addon xul technology, but would they also use old Anti-Virus that does not update. It is a choice we all have.

Security requires the need to update and the change was never going to be totally smooth because addon authors also have the choice on whether they want to proceed or not.

https://blog.thunderbird.net/2017/05/thunderbirds-future-home/ .... I hope XUL and XPCOM will stay supported for much longer than in Firefox. Mozilla wants to kill off this important technology mainly for safety reasons, but a lot of important Addons in the mail area are based on it. ...We will continue to support legacy add-ons for as long as possible. Given our current dependency on the Mozilla Platform and the upcoming changes in Firefox 57, it may become increasingly difficult to support XUL/XPCOM add-ons. I believe there has been some discussion on this topic on tb-planning

Time has since passed since those comments were made and now there has been a huge change.

So in a nutshell, the changes were inevitable to improve security.

Thank you for answering my basic question, it was necessary for security reasons.

Now, without the XUL/XPCOM framework, it would be nice if the core would provide some means for those old addons to still have a way to implement their many great features, that are missing in the core product. For example: - ability to modify the UI elements of a theme (font size, spacing, etc.) - ad blocker support

There is guidance etc for the authors of addons which has been available to them for some time.

one example: https://developer.thunderbird.net/add-ons/tb68/changes

Tom Dietsche said

Thank you for answering my basic question, it was necessary for security reasons. Now, without the XUL/XPCOM framework, it would be nice if the core would provide some means for those old addons to still have a way to implement their many great features, that are missing in the core product. For example: - ability to modify the UI elements of a theme (font size, spacing, etc.) - ad blocker support

UI modifications can still be done with css. There are many examples posted in this forum, such as here.

Ad blocker for TB 68: https://github.com/gorhill/uBlock/releases

It's because the Thunderbird developers don't care about the problems with updating addons, combined with the fact that they keep updating at a breakneck pace (unnecessarily?); far too fast for addon developers to actually fix how the new version of Thunderbird has broken their addon before yet another version of Thunderbird is released.

The reason why there are so few addons for the latest versions of Thunderbird is because most of the addon developers for Thunderbird quit in disgust because the Thunderbird developers have no consideration for the work they do, or the fact that every single one of them are working 100% voluntarily, in their spare time. The vast majority of addon developers have full time jobs, and have neither the time nor patience for Thunderbird's reckless race for the highest possible version number possible.

The Thunderbird Developers need to slow down and take a deep breath, and show some consideration for addon developers. Add to that the fact that they decided to not adapt Thunderbird to use the same kind of addons as Firefox uses, utterly destroying the previous Addon Crossover compatibility the two programs previously enjoyed.

It honestly seems like the Thunderbird Developers are on some sort of power-trip. Yes, they're all volunteers, but so are all the other contributors to Thunderbird, and they need to start to appreciate that.

Bobby, you are spot-on with your insights into the mindset of these core developers. At age 70, I've been developing software for close to 50 years, and I've run into too many developers like these.

The above replies from Toad-Hall and others show their total lack of regard for addon developers. "Oh they can just rewrite their addons, here are the totally new rules, just keep up to date with our changes you non-core-group addon writers."

That totally sucks, I may just give up on Mozilla, the core developers seem to be in an echo chamber and don't realize the impact on both their user base as well as all the well-meaning volunteer addon writers. That is just plain wrong, wake up developers! Otherwise your market share will continue to erode. The core product doesn't have enough of the great features that addons provided becaue you don't live in the real user world, you live in some developer idealist fantasy world and add pointless features that seem great to you but that users hate. Get out of your mother's basement and talk to real end users, you will be amazed.

Bobby, you are spot-on with your insights into the mindset of these core developers. At age 70, I've been developing software for close to 50 years, and I've run into too many developers like these. The above replies from Toad-Hall and others show their total lack of regard for addon developers. "Oh they can just rewrite their addons, here are the totally new rules, just keep up to date with our changes you non-core-group addon writers." That totally sucks, I may just give up on Mozilla, the core developers seem to be in an echo chamber and don't realize the impact on both their user base as well as all the well-meaning volunteer addon writers. That is just plain wrong, wake up developers! Otherwise your market share will continue to erode. The core product doesn't have enough of the great features that addons provided becaue you don't live in the real user world, you live in some developer idealist fantasy world and add pointless features that seem great to you but that users hate. Get out of your mother's basement and talk to real end users, you will be amazed.

That's the problem, and your frustration with the Thunderbird Developers is exactly why so few people are willing to go through the ordeal and headache of trying to develop and/or update addons for Thunderbird. I hope you don't give up entirely, despite the Thunderbird Developers giving you every reason to do so. We, the users DO appreciate all the work the addon developers do, and support you all, despite the Thunderbird Team's egomaniacal contempt for you.

I am a Thunderbird user. I have used addons that are no longer working. In some cases css code has fixed the issue. In other cases eg: in helping sort out font size, the developers have included a means of sorting this out within Thunderbird.

Whether I am frustrated by some addons not functioning is not relevant, but it would not be too difficult to assume I am disappointed to say the least.

I have knowledge about why the changes were necessary in Thunderbird and I'm not that unintelligent to understand that they were inevitable, necessary and could not be avoided. So I accept the changes.

I have knowledge about all the various reasons why some addon authors have chosen not to upgrade. I respect their choice and feel for them.

When I post information, I do my best to not get emotional and just supply information on why things occur.

re:The above replies from Toad-Hall and others show their total lack of regard for addon developers.

Do not assume that because I try to keep to the facts to answer a question means I am not aware of peoples' frustrations and disappointments, but casting inappropiate aspertions is disrespectful and not appreciated. Like those people who create the addons, I have also spent hundreds of hours, nay thousands of hours helping people for free and there are times when not everyone appreciates the value of what they receive.

I apologize for the personal comments, and I appreciate all the time you spend on this, but I am just so d**n frustrated with the design mindset at Mozilla. Both Firefox and Thunderbird market shares keep going down, I believe, and it has a lot to do with this.

A response like "it can be done by tweaking the css" is a great example. Yes I, unlike 99% of normal end users, do understand css and how to change it, but why in the world would I want to do that when I could just install a point-and-click addon that will do exactly what I want without spending a lot of time experimenting and testing with css code when I could get it done in a couple minutes with a 3rd party addon that does something simple that Mozilla didn't think was important.

If Mozilla REALLY wants to improve market share, open it up to addons and extensions by putting in hooks and plugin-friendly features that let developers improve it. It is far from perfect right now. Here's a great example: WordPress. They became the dominant website developer platform by inviting and loving their extension partners. They make it easy and they provide an optional certification process as well. That's what I would like Mozilla to do, but it seems to be a closed echo chamber. How does that internal development philosophy ever get changed when the inmates are running the asylum? That's my question.

Thanks for continuing the dialog!

I am a Thunderbird user. I have used addons that are no longer working. In some cases css code has fixed the issue. In other cases eg: in helping sort out font size, the developers have included a means of sorting this out within Thunderbird. Whether I am frustrated by some addons not functioning is not relevant, but it would not be too difficult to assume I am disappointed to say the least. I have knowledge about why the changes were necessary in Thunderbird and I'm not that unintelligent to understand that they were inevitable, necessary and could not be avoided. So I accept the changes. I have knowledge about all the various reasons why some addon authors have chosen not to upgrade. I respect their choice and feel for them. When I post information, I do my best to not get emotional and just supply information on why things occur. re:The above replies from Toad-Hall and others show their total lack of regard for addon developers. Do not assume that because I try to keep to the facts to answer a question means I am not aware of peoples' frustrations and disappointments, but casting inappropiate aspertions is disrespectful and not appreciated. Like those people who create the addons, I have also spent hundreds of hours, nay thousands of hours helping people for free and there are times when not everyone appreciates the value of what they receive.

And yet, rather than work WITH the Addon Developers, you choose to work IN SPITE of them. Why did you not give ample time and consideration to the Addon Developers early on, instead of just pushing on so quickly? I have spoken with many former Thunderbird Addon Developers and they gave up on developing their addons because the attitude they got from the Thunderbird Team was that "it was our responsibility to deal with whatever things about our addons that had been broken by the rapid flow of updates, and to not complain about it", and that"The Mozilla Development Team Is all volunteers" was thrown at them almost rudely, giving the impression that the Thunderbird Development Team didn't appeciate that the Addon Developers weren't as much of an important part of Thunderbird overall as the core app developers.

The previous thing that most Thunderbird users enjoyed about the app was it's huge customization potential with addons, unlike the other Email Clients available. The fact is, you DID alienate Addon Developers, and as a result, Thunderbird's popularity is waning fast, resulting in making all your work on it for naught.

I am not casting inappropriate aspersions; I'm supplying a perfectly appropriate WAKE-UP CALL. You need to start working WITH Addon Developers, rather than casting aspersions yourself on them that they should just adapt to what you and the Thunderbird Development Team does without considering their input, frustrations and issues.

You can't be a Lone Gunman on this; the Core App Developers and Addon Developers need to be working as a Cooperative Team. And big and fragile egos have no place in a Team.