Manage Exceptions button for cookies is not working for me since FF88 or 89, don’t remember which version precisely. I click on the button and the dialogue box that would normally appear to set exceptions does not pop up. Moreover it looks like when I click on the button the user interface on that tab freezes for a period. My FF profile is customised. I know if I start with a blank profile the issue goes away. However I would rather try to fix this issue in my current profile. I poked around in about:config but so far have had no success.
Any ideas? I searched google but could not find anything. Also checked bugzilla a while back without success. I am using FF 92.