An Enterprise user recently reported a problem with Firefox 140 esr switching to the regular release. That definitely is not supposed to happen -- an external updater might be involved. https://support.mozilla.org/questions/1530688

Is Firefox 140 esr installed in parallel to the regular release of Firefox anywhere?

If not, can you uninstall Firefox 142 -- if given the option to remove data, say NO! -- and reinstall Firefox 140 esr? https://www.mozilla.org/firefox/all/desktop-esr/

Firefox was installed just once in October 2021 when this PC was purchase and the old profile from my Windows 7 machine copied. All updates were done thru the about, update when I got the notices. The link preview is not there for me in use or in the settings. Is it only the regular release that changed the behavior of the tab groups collapsing and leaving one tab open?

Thanks, Mike

Link Preview: if browser.ml.linkPreview.enabled was never set to true in about:config, then the checkbox to enable/disable Link Previews is not present on the Settings page.

Tab Groups: it is new in Firefox 142 that if you collapse a group containing the active tab, Firefox keeps the active tab active instead of activating the first tab after the group.

So is there a way in Firefox 142 to set in the about:config or somewhere else the Tab Groups back to the previous behavior of totally collapsing the group to save screen area?

If I installed Firefox 140 esr and got it to update to v142esr would the Tab Groups totally collapse like when the feature was initially introduced or would the v142esr have gotten this new behavior of leaving 1 tab open?

As far as tab groups collapsing, I had no tab groups defined so decided to try it out. It seems that if you click a group label, it will collapse it all the way if you are not focused on one of its tabs.

If you click on a group label that has one of its tabs focused, then that tab keeps showing with a number beside it. If you then click on a tab that is not part of the group, then it completely collapses.

So, it would seem that if all groups are collapsed there should be just one showing with a number beside it, unless you collapsed them while viewing a tab that's not in any group.

I was only testing this out with 2 groups with several tabs in each. If there is a way to change this behavior, I'm not sure of it.

So is there a way in Firefox 142 to set in the about:config or somewhere else the Tab Groups back to the previous behavior of totally collapsing the group to save screen area?

I'm not aware of one. You have to make a tab outside the group active to allow the active tab to collapse.

If I installed Firefox 140 esr and got it to update to v142esr would the Tab Groups totally collapse like when the feature was initially introduced or would the v142esr have gotten this new behavior of leaving 1 tab open?

Reinstalling would not change the behavior.

Thanks for all the tips. I tried selecting another open tab and it does solve the problem. The Tab Group feature has been a big help being able to have a lot of tabs in groups so I can shut down at night instead of hibernating which has to save a large file on the solid state C drive. It was a feature I didn't know I needed!

What is the danger of not being on the ESR channel, will I get all new features as soon as they are tested on Nightly first? If so will the reinstall get me back on the ESR v142? Version 142 ESR really exists?

There is no Firefox 141 ESR and 142 ESR as the most current ESR is 140.2.0 ESR (came out when 142.0 was released) which is based on the 140.0 Release but with allowed stability/security fixes.

The Fx 141.0 and 142.0 (currently at 142.0.1) has been only on Release channel. The previous major ESR version is based on the Firefox 128.0 release and is currently at Fx 128.14.0esr and is the last update as it will be EOL on Sept 16th. The older Firefox 115 ESR branch is at 115.27.0esr and may be the last for Windows 7, 8, 8.1 macOS 10.12, 10.13, 10.14 OS users unless Mozilla decides to extend updates a third time before Sept 16. https://whattrainisitnow.com/release/?version=esr

https://www.firefox.com/releases/ https://www.firefox.com/download/all/

Release < Beta < Nightly (Developer Edition is same as Beta channel but with additional developer features).

Perhaps a reason why you updated to to the Fx 142.0.1 Release is because you were using the Firefox 140.0.x or 141.0.x Release and not the Firefox 140.x.0esr

I had thought I went from 128 esr to 138 esr but maybe I didn't notice that the esr was missing. What version had the tab group option introduced?

I had thought I went from 128 esr to 138 esr but maybe I didn't notice that the esr was missing. What version had the tab group option introduced?

Tab groups have been in Firefox for a while, with little tweaks in each new version. I'm not sure of the precise differences between Firefox 140 and Firefox 142 (other than the new active tab behavior).

If I were to install the 140esr release I would need to preserve my screen layout, bookmarks, saved tab groups and passwords. Is this accomplished by just saving my profile before a reinstall and copying it back or do I need to move some contents from the within the old profile I have been using? I currently have 2 profiles in about:profiles. 1 ends in default.release which is the current in use and 1 ending in default which must have been from the initial installation when the PC was new. It's only 42MB while the default.release one is about 2GB.

If I were to install the 140esr release I would need to preserve my screen layout, bookmarks, saved tab groups and passwords. Is this accomplished by just saving my profile before a reinstall and copying it back or do I need to move some contents from the within the old profile I have been using? I currently have 2 profiles in about:profiles. 1 ends in default.release which is the current in use and 1 ending in default which must have been from the initial installation when the PC was new. It's only 42MB while the default.release one is about 2GB.

Maybe you have not used the ESR release because its profile is normally named something like default-esr.

Generally speaking, you could copy/replace files in your new default-esr profile with files from default-release and it should work UNLESS the file format was upgraded in a way that makes it not backwards compatible. There really isn't any obvious way to reseach that; since only 2 months have passed, my guess is that nothing drastic has occurred, but I can't be sure.

See: Restore bookmarks, passwords, and data from an old Firefox profile

Confused because i was just on 128.14. accepted the update via prompt, and now it looks totally different. did they rush this out and skip versions? Also its sluggish and font looks weird, and the tab previews are just distracting. somethings not right. But for security reasons we are kind of forced into using this mess. Yes its a mess in my opinion. Looks like its back to searching forums and googling how to undo this .

Confused because i was just on 128.14. accepted the update via prompt, and now it looks totally different. did they rush this out and skip versions?

Once you choose the Extended Support Release track, it is normal that there is a major update about once a year. Firefox 140esr is based on the feature set of Firefox 140, released in June.

Also its sluggish and font looks weird, and the tab previews are just distracting.

For tab previews, if you mean the enlarged tooltip when you hover over a tab, you can remove the images using a checkbox on the Settings page:

[_] Show an image preview when you hover on a tab

For performance and font issues, I suggest starting a new question:

https://support.mozilla.org/questions/new/firefox/form

Thanks jscher2000 I was able to disable both font preview and image tab preview.What an odd feature to add. My bad for jumping on the thread and letting my emotions get the best of me. Appreciate your advice. I think the font and graphics are just a new look, and may take sometime to get used to. Just not a fan of them.