In the latest Firefox version(116.0.2 (64-bit)) the button “List all tabs” won’t show any tabs unless I close like half of them, then it works again if I open new random tabs. Currently 246 open tabs.

Any other way to fix this? I don’t really wanna close those tabs.

The way I know this is that I tested in a sandbox with the same profile to try to find the problem.

EDIT 14/Aug/2023: So I just found out the issue was some tabs that had a " --" at the end of the title probably caused by some addon made this issue happen. It probably isn’t really a - but I don’t know what character is that.

All you have to do is just copy the url, open a new tab, paste the url and go. Close the previous tab with " --" at the end.
Just make sure you are not opening a new tab with CTRL+(clicking the + icon) from the “broken” tab with the " --".

Example.

Hope this helps someone else.

    • ChapoOP
      1•1 year ago

      I also can’t reproduce with a new profile.

      I literary copied my profile from %appdata% and pasted it in Windows Sandbox %appdata% for testing.

      First i removed the chrome folder, could be the userChrome.css, nothing.
      Second i removed all the extensions but the problem persisted, then i started closing tabs and at around 147 tabs closed it fixes it.
      It crossed my mind it could be some extension that did something to a particular tab or something that breaks the list but it doesn’t seem coming from a specific tab.

      This only started a couple of days ago, probably when Firefox updated, not sure.
      It also messed up a bit the userChrome.css where i had custom separators a bit where i fixed with the line “padding-block: 0px !important;”.

        • ChapoOP
          1•1 year ago

          I actually just fixed it, the problem came from tabs with a " --" at the end of the title, probably added from some addon. Please check the edit above for more info.

            • dannycolin
              1•1 year ago

              I tried to reproduce it (directly from a local build) with no luck. Any chance you can share your list of addons and userChrome.css?