Some sites I use frequently have not worked on new Firefox versions for the past year or more when you disabled and then messed around with working offline, then disabled reloading all tabs once going back online. So I was forced to go back to an old version of FireFox.
Now I am having serious problems because of all the ads since AdBlock no longer works and can’t be reloaded (FF says it is corrupted). Also I need other add-ons urgently.
Your fix only works for the latest version of FF (and it looks like it doesn’t even work on that if the posts are to be believed).
Please issue a fix that will work on old versions. Otherwise, I will have to abandon FF as my default browser and only use it for the specialised sites.