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Important update! On March 14, 2025, a critical root certificate in Firefox will expire. If you’re still using an older version (before Firefox 128 or ESR 115.13+), it’s crucial to update to Firefox 128 or newer to avoid issues with add-ons, DRM-protected content, and other features.

For full details, check out Update Firefox to prevent add-ons issues from root certificate expiration.

If you have questions about the update or need help with the process, this is the place to ask! Whether you’re just starting or you’ve already updated and want to share your experience, we’d love to hear from you.

Let’s come together, share tips, and ensure we’re all prepared. Drop your questions or insights below!

Good morning, I had asked a question early on Saturday, but was unavailable the rest of the weekend so just now responding to associate Corey Bryan's answer. I had gotten a message that I am using an unsupported version and they recommend downloading the latest stable version.

He said it appears that I'm on the "Release" channel and most likely want to be on the ESR channel. I also mentioned that I am a cave-man when it comes to anything computer and am very skittish about making any changes as I don't how to straighten out any errors that might occur.

He asked me where I installed Thunderbird from and the answer is that I don't know. It was an IT guy that did it many years ago.

So I guess my questions are, if I've been using this version for years, do I need to or should I update it? If so, if I click on the latest stable version of Thunderbird, will that change anything on my computer, aside from getting the newer version of T-Bird? And will my e-mails in Thunderbird look any different?

Thanks very much for the help. Tony

I just upgraded to 128.2.2esr and cannot receive or send messages after the update. I have restarted the computer and tried again - still nothing. I'm unable to use a tool that is critical for my daily needs.

Trying to send just says "Connected" or "Sending" but never completes. Worked fine before the update which was just in the past hour or so.

Same issues with downloading new email or sending email for all accounts. :(

Anyone else having problems? Ideas?

Thank you!

About a month ago I began the process of upgrading from W10 to W11. In the process, several problems happened. One of the problems was with Firefox. After reading and trying many suggestions from the Mozilla site, as well as several other sites, and having no success, I posted my problem on this Mozilla support site and hope that there was someone who could help. There was. After several days of exchanging messages (suggestions, instructions and results - mostly about Profile), Firefox returned.

The other major problem is Thunderbird. I have downloaded a current version (128.5.2esr). I have run it twice and, each time, email was downloaded. So that part seems to be working. What doesn’t appear are the settings I have used and message folders I have created over several years. I suspect that the problems are Profile related.

Starting from Help in the Thunderbird menu, then Troubleshooting Information, then Application Basics, I see Profile Folder. On that line is a button labeled Open Folder followed by (Local Drive). I click Open Folder and File Explorer opens to a folder named ab3xaztm.default-esr. It shows that the folder contains 59 items, including 10 subfolders. All files and folders show a December date.

Following the path C:\Users\rsuth\AppData\Roaming\Thunderbird\Profiles\, in addition to ab3x…, there is another folder nlys3gkl.default that contains only 1 file, times.json.

Because of my earlier struggle – and eventual win – with the Firefox problem, I think that the Thunderbird problem might also be fixed in a similar way: Profile.

Slightly before the upgrading from W10 to W11, I made a copy of my Thunderbird folder. I think if I replace the currently active Thunderbird folder with the one I have saved, my Thunderbird problem may be over. However, I’m not certain that will happen and I’m not certain about the specific steps to take to make the replacement. (With my Firefox issue, there were a couple of small important steps I had to take to make it work, and those steps were explained to me by the person who helped me with my Firefox problem. So, after all these words, can someone point me in the direction to solve my Thunderbird problem?

Thanks for reading.

Hello, I've got the french version of Thunderbird on my laptop. I want to have it now on my smartphone Android. But impossible to find the function "move to mobile" in the parameterss... Please help me !

A few weeks ago after an automatic update I ended up having Thunderbird version 131.0.1 installed, I have no idea how this happened. On opening I get a message telling me I shouldn't be using a beta version and that I should revert to the latest general release version (128.4)

Today when I had some free time I downloaded 128.4 and installed it. On opening it it says that I can't use a profile file from a later version with the earlier version. Is there a way to recover from this WITHOUT having to set up the whole profile again from scratch.

Meanwhile I have done a system restore so I am back with 131.0.1 It has not given me any problems so far. Is there a new general release version imminent that will get me back on track?

I would appreciate any help I am not a computer expert, just a user, and find Thunderbird a very good email client.

David Gould

I've never knowingly installed a non-mainline thunderbird, but earlier this week I started getting the following when I open Thunderbird:

This is an unsupported version of Thunderbird!! Thunderbird monthly releases are not considered stable for general use. Use at your own risk, this build is the same quality as Thunderbird Beta.

Checking the version of thunderbird.exe It says its v131, which happens to be the same as the copy of Firefox installed. When I remove and reinstall Thunderbird it starts off as 128 but quickly changes to 131, even after uninstalling Firefox. (Also annoyingly, this stomps on the version in the profile, which 128 claims is no longer compatible, because Thunderbird isn't clever enough to save a copy of files when it makes "breaking" changes to user files)

I wouldn't being on 131 if actually worked, but it gets stuck in the handshake with my IMAP server, and doesn't even show the local folder caches. (It also for some reason shows the window controls on left side of the window title bar, rather than the right).

How can I restore standard functionality?

In Windows 11, the Address Book is accessed via an icon on top left of the TB main page or Alt+2. In Windows 11 is there a similar key combination to view the folders below Local Folders?

Dear Thunderbird team I am an avid user of TB (home desktop Windows PCs), but I have been resting on my laurels on v78 for a few years now. I know, shame on me. I would like to upgrade to a stable "modern" release (emphasis on "stable" please). Can you please advise if I should aspire to end up on 115 or 128, and how I might get there ? From reading some older blogs, there is advice that says.... first go to v91, then v102, then v115, and so. That seems a bit tortuous, but I am happy to do so if that is still the recommended approach.

Also, can you advise on how I manage my Profile through all this, do I need to do various exports/imports as I move through these different versions, etc.

Many Thanks

I recently got a new computer, Apple iMac. I'm trying to transfer all my bookmarks I have on my older HP computer to the newer computer Apple. I downloaded the Firefox browser to the iMac. I see where there is a link to transfer bookmarks when I loaded the browser. But, when I click on the link, nothing really happens? There is no transfer of my bookmarks for my old computer to the newer computer. My OS with my older HP was Windows 7. My OS with my acquired Apple is Monterey. Can someone be of help with transferring bookmarks from one computer to another? I have many bookmarks so it would be very helpful to be able to make that transfer. Thank you.

I am on 115.13.0 (32-bit) yes, and oddly it says updates disabled by system admin (that's me). I have no idea how to change that. No way I took steps to disable thunderbird updates. I found only one thread on how to reenable but it was very vague and the OP did not arrive at a perfect fix.

I'm trying to transfer the Profile folder from my current laptop to my new one. I followed the directions here: https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer but must've made a mistake because none of my many Local folders have populated Thunderbird in the new laptop. Also, the GB size, number of files and number of folders show to be very different on the new laptop vs. the current one.

I'm inclined to just start over but have a question. Can I simply delete the contents of the "Thunderbird" folder under "Roaming" in my new laptop and try again to paste into it? Or are there some items in that folder that were inserted when I first downloaded TB into my new laptop so that doing a complete deletion would remove those and they wouldn't be replaced when I try pasting again? If so, how do I get around that?

Thanks very much for your help.

Since yesterday I have Thunderbird nebula 128.2.3esr on my Windows 10. But I cannot find my calendar and the new left sidebar isn't available, but only a little button on the left upper corner with seven button without function. I've tried a lot, I cannot find any description about a same failure in the Internet.

I am about to set up a new Windows 11 laptop. The old one is a Win10 one, running Thunderbird 128.4.3 32-bit. Note I haven't upgraded to 5.2esr yet. My Thunderbird profile as recorded by Mozbackup is about 16GB - most of this is archived in Local Folders. I have 15 email accounts (using four different domains, none of them are gmail or hotmail etc) and a newsgroup.

I've looked at various answers (and problems!) around these factors and cannot see the wood for the trees. Can anybody tell me - or direct me to - a clear description of how to go about this? Some questions are:

1. Can I install 64-bit on the new laptop and copy over the old 32-bit profile? If not, is there any problem in continuing to use a 32 bit Thunderbird? I am getting a lot of hanging/not responding in the current TB. Note I haven't upgraded to 5.2esr yet.

2. How do I ensure that all the archived mail is transferred without problems? I haven't compacted anything lately, since I noticed that sometimes a message stub is retained where the message body seems to have disappeared, and that compacting risks deleting even the message stub, which can be useful.

3. I've been using MozBackup for ages now but it is really ancient - is there a more up-to-date backup that would be reliable?

Thanks in advance! I'm planning on do the new installations at the weekend but anything I can do to prepare would be useful to know!

Kate

A new version of the "List All Tabs" appeared on my toolbar today, shown on the left and hovered over in the attached screenshot (ignore the Malwarebytes extension icon). The old icon for this button was a chevron with approximately the same functionality. I was able to remove the old icon, but I'm unable to find a way to remove this one. Here is what I've tried so far:

• Like the old one, the Customize Toolbar feature is unable to remove it since it is grayed out.
• For a while, I was able to remove the old icon by going to about:config and setting browser.tabs.tabmanager.enabled to false. This solution does not work for the current and some recent versions of the button.
• I attempted to create a userChrome.css file (following all the steps according to this this website) and added the following string: #alltabs-button { display: none !important; }

None of these attempted fixes have removed the button following a browser restart. Is there a way to remove it? I have no need of a button that shows me what tabs I have open when I can simply look at my toolbar.

I know that typically mozilla does not put a low bound on advisories, and https://www.mozilla.org/en-US/security/advisories/mfsa2024-40/ is the advisory for vulnerabilities fixed in ESR 128.2. CVE-2024-8387 is listed here. yet the advisory for 115, https://www.mozilla.org/en-US/security/advisories/mfsa2024-41/ does not list this vulnerability. Was this something that was only impacting 128 (for the ESR builds) or is there a mistake that either 115.15 did patch it but it wasn't documented, or the patch has been missed and ESR 115 is still vulnerable?

I've been on Thunderbird for almost 20 years and a Mozilla fan. Have evolved a fairly elaborate configuration of local (POP) email folders, rules, calendar, and accounts to manage & organize email activity, retention, archiving, etc. I've not had to deal with Profiles in previous upgrades and don't have much experience with it.

The recent Oct 1 push of Firefox & Thunderbird 131.0 releases took me by surprise. I was able to re-implement the previous Firefox profile to recover bookmarks, cookies, passwords, etc. However, when T-Bird warned that 131.0 was Beta & unsupported I took the suggestion to download & install the current supported release: 128.3.0 (I was on 128.2.3). Then hell came.

Once downloaded, installed & launched, Thunderbird 128.3 cautioned the new profile created with T-Bird 131.0 was incompatible with previous versions and that I should create a new one, which I did. Still could not get new T-Bird to recognize previous profile, so I tried uninstalling, downloading & reinstalling 128.3 multiple times, each time prompted to create a new profile before proceeding. I tried to follow the previous profile restoration process detailed on support forums & articles, but none seemed specifically relevant to my situation.

I located my profiles in the appdata roaming profile folder, including what I think are most recent based on size of mail folders. Can't determine whether I had just one or several in use due to the extent of my setup. Could really use some help & advice to: 1) Determine which profile was in most recent use prior to T-Bird upgrade. 2) Whether more than one profile was in use. 3) Re-implement the profile I was using on T-Bird 128.2.3 with my new 128.3.0

Regards & many thanks in advance, John C Houston

PS You'll ask why I would upgrade to 131.0 from 128.2.3. Answer: it was on auto-update and 131.0 is what was pushed. No more auto-updates for this guy!

I have a custom pitch black theme ( pls add it without addons ) which now only flashes for a second when i open the browser and returns to the normal greyish dark mode. When i go to Firefox Color addon page and load it again in saved themes it stays pitchblack even if i open another browser window until i close all the browser windows .

A friendly hello to whomever is kind enough to read this! Your help is greatly appreciated!

The latest update caused an edit I made to my Profile's userChrome.css file to be nullified. Now there's huge bar where the tabs toolbar used to be, and apparently it's not the title bar, as when I activate the title bar in "Customize Toolbar," this huge gets replaced by the actual toolbar.

I've attached my css code below for inspection. It used to work perfectly, but after the last update (133.0) it's no longer working. What can I do to fix this and have it like I had it prior to the latest update (133.0)?

userChrome.css File: `#main-window[tabsintitlebar="true"]:not([extradragspace="true"]) #TabsToolbar > .toolbar-items {

 opacity: 0;
 pointer-events: none;

}

1. main-window:not([tabsintitlebar="true"]) #TabsToolbar {

   visibility: collapse !important;

}

1. main-window[tabsintitlebar="true"]:not([extradragspace="true"]) #TabsToolbar .titlebar-spacer {

       border-inline-end: none;

}

/* Adding empty space for buttons */

1. nav-bar {

margin-right:140px; }

/* 15px for dragging whole window by mouse*/

1. titlebar {

appearance: none !important; height: 15px; }

/* Fix for main menu calling by Alt button */

1. titlebar > #toolbar-menubar {

margin-top: 10px; }

/* Move minimize/restore/close buttons to empty space */

1. TabsToolbar > .titlebar-buttonbox-container {

display: block; position: absolute; top: 17px; right: 1px; }

1. sidebar-box {

 min-width: 250px !important;

}`

It seems from reading on forums and googling that there is a "return receipt" function in Thunderbird. My problem is I can't find it anywhere in my software. I've searched in every category and can't even find an "Options" on the menu. I remember when Thunderbird did have a "return receipt" that was very easy to find. Now it seems that it has disappeared altogether. What gives?