Yesterday (Sat 5/31), I woke up to the 139.0.1 update, along with a new behavior that Firefox will hang (and require a Force Quit) any time I click a pinned extension that opens a drop-down interface (e.g. 1Password, Adblock Plus, Pocket). I've tried disabling all extensions and bringing single ones back (as well as disabling Pocket via about:config) - the result: any extension that opens a dropdown causes the hang, and any extension that runs without opening a dropdown works just fine, regardless of the combination of extensions that are enabled/disabled at the time. I tried opening Troubleshoot Mode (although it's of little use since my problem seems rooted in extension behavior) - the first several times I tried, it ALSO caused a hang, but now I'm able to turn it on & off without an issue (though the page rendering is wonky within it - I imagine that's just a Troubleshoot Mode thing?). For whatever it's worth, I think the change that preceded it starting to open without hanging was my disabling this [[https://support.mozilla.org/en-US/questions/1182594|"resume_from_crash" setting]] (though it didn't cause any change in the original behavior, which was my initial goal). I'm running macOS 14.6.1 if it's of any use. Thanks for any troubleshooting ideas!