I am having some difficulty in killing profile sessions. using the kill debug boutton does not seem to do anything and i must restart firefox to be able to stop debugging. Not a total disaster but a minor inconvienience.

Hey the link is not working and i can't find the extension anywhere.... i use Firefox 66 .. whats going on?!!? What i supposed to do with this software without a debug bar?!

It's up to Mozilla guys to keep or delete modules or relocate them into other directories.
It was 3rd party extension, open source -- cause there are only html/js/css files in it, absolutely harmless, but nevertheless the link stopped working. What a shame.
Please contact Mozilla and / or original author

Debug bar may be useful to some people, but I've been using PhpED for years, have never used a debug bar and have never had a problem with debugging. I just use F9 and Ctrl+F9 to start sessions as required. I will sometimes have multiple browser windows, each with a DBGSESSID in the URL for either debugging or not debugging, then just refresh those windows as required. Fast, easy and convenient.