I'm presently running Firefox 47.0.1 on Mac OSX 10.6.8. I see in an archived (locked) thread that other users have had similar problems with Firefox updates related to "Chrome" add-ons or extensions. In my case, the first Firefox 47 update (and thereafter) triggered nearly complete Firefox dysfunctionality: Firefox would be completely unresponsive for as much as 20 or 30 minutes; it would consume 95-120% of CPU core usage for this whole while (a reported 120% = 100% of one processing core + 20% of another); and CPU temperature would go through the roof for that whole while — my system would get so hot that I was regularly forced to force quit Firefox (which refused to respond to "Quit"). Unable to fix this problem or use Firefox for the next few weeks, I very reluctantly had to resort to using Safari for this time — even though most of my web-browsing usage depends upon chronicling vast research with a vast organization of bookmarks (which made continuing all present work impossible). During this time, I found Safari's handling of bookmarks preclusively cumbersome... so, I held out hope I could get my Firefox installation working well again. I have since learned that I could have fixed my problem right away: I had assumed, since this dysfunctionality coincided with an automated update, that the fault was faulty new Firefox code; and thanks to this (wrong) assumption, I also presumed that I was not going to be able to use Firefox any longer — at least until updates *may* have fixed its wholly dysfunctional behavior. My bad, evidently — but not a completely irrational assumption, in that the dysfunctionality coincided immediately with an update. I am thus posting my question both to inform others of ready solution, and to ask Mozilla users or developers how we might more efficiently identify an offending add-on? I HAVE SINCE FIXED THE PROBLEM, thanks to a post I just discovered here at Mozilla Support: https://support.mozilla.org/en-US/questions/746499 By interpreting the identifying term, "chrome" in the error message, this thread very helpfully advises to disable Chrome add-ons. I then searched for how to disable "Chrome" add-ons... and found no useful information. My question is, "how do we identify Chrome or other types/classes of add-ons"? The unresponsive script warning reads, "A script on this page may be busy, or it may have stopped responding. You can stop the script now, open the script in the debugger, or let the script continue." Firefox was regularly unresponsive to clicking any of these options for over 5 minutes. Even then, you had no idea if it was ever going to finish whatever it may or may not have further engaged in doing. In my case, I was readily able to presume the offending add-on, because the "Warning: Unresponsive script" message was raised regardless of whatever tab was focused of over 100 tabs — *including the customize toolbar tab* (for example). Inasmuch as I presumed the latter (example) related to no conventional page... and realizing that I had just *one* add-on which might, at startup, have wanted to analyze material in every page... I clicked on that add-on. The add-on was Grammarly. I tried to search the add-on for "Chrome," to identify if it was a "Chrome add-on" — but no luck: No search box. So I just disabled Grammarly, re-started Firefox... and poof... no more problem. I think it would be helpful therefore if Firefox developers could comprehensively document: 1. How to comprehensively interpret the Unresponsive script error messages; 2. How to identify and to shut down offending tabs (pages); 3. How to identify and disable types or classes of add-ons or extensions (if an add-on or extension is the problem). Meanwhile, I'm very happy to report that I am back up and running — and even moreso... happy to be able to continue to use the extensive system of bookmarks which chronicle my research.