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 " --".
Hope this helps someone else.
I wasn’t able to replicate the error by adding one or two m or n dashes to the document title. Based on this error message and the screenshot, and comparing how Firefox displays other tab titles when Multi-Account Containers is installed, I wonder if the problem tab was open in a container that had been deleted or had become corrupted in some manner so Firefox had retained the assigned container ID, but that container ID no longer matched any container. Opening the URL in a new tab most likely used a different container, working around the problem.
UPDATE
I filed a bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1848877