1986699 - Tab closes when adding it to an existing group.

Status: UNCONFIRMED

(Firefox :: Tabbed Browser, defect)

Description

[Tyson Gillispie]

Attachment: fastfetch9-3-25.png

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:142.0) Gecko/20100101 Firefox/142.0

Steps to reproduce:

I am running on CachyOS, my fastfetch will be included.

I go and right click a tab and hover over Add Tab to Group, which opens the sub-menu where I select to add the tab to a previously closed group. I'm trying to add my tab with YouTube open to the group Media that I used previously.

Actual results:

Immediately after selecting Media the tab crashes without an error displayed or any indication of what happened. I'm not so inclined to go the log and find out myself. This causes there to be multiple Media groups in that sub-menu that I cannot delete.

Expected results:

Add the tab to the existing group and go on with my day

Comment 1

[Stephen Thompson [:sthompson]]

Hi, Tyson. I'm unable to reproduce on Nightly 144.0a1 (2025-09-02) on macOS. There shouldn't be any relevant platform-specific issues, but I suppose it's possible.

I'm able to create a new tab group, save and close the tab group, open a new YouTube tab, right-click the YouTube tab, choose Add Tab to Group, and select the tab group I just closed. The YouTube tab closes without errors. When I reopen the tab group, it contains the YouTube tab.

Have you had the Media tab group saved and closed for a long time? Do you have any open tab groups in your tab strip?

It sounds very strange to end up with multiple Media tab groups listed in the Add Tab to Group sub-menu. Tracing the code, I'm not sure where that could happen -- it seems like the Add Tab to Group sub-menu is being rebuilt each time from the list of saved-and-closed groups, and it doesn't seem like the click handler for that sub-menu can have a side effect of adding a new saved-and-closed group. The tab crash could be caused by some problem during tab removal, but it's hard to know without more information. If you are able to open the browser console after reproducing this and you find a JavaScript error coming from the browser code, that would be helpful.

Comment 2

[Tyson Gillispie]

Attachment: ffbug.png

Comment 3

[Tyson Gillispie]

So I'm not sure if these errors are from when i create the process in the first place or if it's when I try to add the tab to a existing group, but here is my console. If this isn't what you're looking for let me know.

Comment 4

[Stephen Thompson [:sthompson]]

Thanks for the additional information. I don't see anything in the console that's obviously related to the process for adding a tab to a saved-and-closed tab group. Perhaps the code is not running into any fatal errors, just logical errors.

I'm not exactly sure what to recommend. Can you reproduce this in any of the following scenarios?:

1. Create a new tab group, save-and-close it, then add a tab to that group
2. In a fresh profile, create a new tab group, save-and-close it, then add a tab to that group

If you're able to do (1) with your existing profile, then there may be a data issue with your saved tab group. The best way I can think to troubleshoot this is to inspect your session data for any irregularities, but the session file contains sensitive data, so I don't want to recommend that. If both (1) and (2) fail for you, then it would be very puzzling. At that point, we might need to investigate platform-specific issues.

How did you install Firefox onto your system?

Comment 5

[Ina Popescu, Desktop QA]

I tested this on Firefox 144.0 on macOS 15 and Ubuntu 22.04 but wasn’t able to reproduce the issue as the tab was added to the existing group as expected. Waiting for the reporter to provide the troubleshooting details requested in the previous comment if the issue still occurs on his side.