I understand that difficulties with Lightbeam have arisen beginning with FF 56. However, no indication of this has been added to its listing in Firefox Add-Ons, nor has anyone from Mozilla familiar with the Lightbeam commented on the fact that it hasn’t been working in awhile. Indeed, it is still available for installation with no mention that it currently is broken.
I suggest Mozilla take one of the following actions. Either remove Lightbeam from the list of available extensions until it is fixed, or add a notation at the beginning of the listing indicating that it does not currently work but that it is being repaired. If simple enough to do, you could also automatically disable it for users who have already installed it, with a notation that it would be enabled when repaired.
I can only imagine how complex constantly updating an improving Firefox must be. But PLEASE! Communicate with your users, especially those of us with less formal tech training. It can become quite frustrating as a user and supporter of FF to see reports of problems like those some of us are experiencing with Lightbeam that go back as far as five months, yet no with no authoritative response from Mozilla.