I stabilized on Firefox 33 some time ago, because it was stable and the rate-of-change of new releases was too fast (which caused me to lose productivity). I want to migrate towards Firefox 64-bit. Should I ... A. Upgrade from v33 to the current 32-bit release in one jump? (Is that even possible?) or... B. Upgrade from 33 to 34, 34 to 35, etc. over time - which means I'll get the "opportunity to experience" :( whatever bugs exist in all the incremental versions... and it will consume a lot of precious time. Are those intermediary versions even available? "Where" (in the big-picture of that process) would you recommend I make the jump to 64-bit Firefox, with the least "upgrade pain?" Non-obvious considerations: 1. I have a dozen add-ons, so path (B) will be very tedious as I need to implement and test each add-on on each version. 2. Is there a matrix available, to show which add-on versions work reliably with which Firefox versions? 3. NoScript is very important; I'm currently at release 2.9.0.3 ... which is also not current (2.9.0.11), but probably more-current than Firefox 33. I'm in touch with Giorgio, the developer, about that. This question is *provoked* by... a sudden failure of Firefox 33 to work (after behaving reliably for years). The symptom was, I suddenly couldn't login use either Yahoo Mail or Facebook (and -only- those two sites)... Facebook would accept the login but do literally nothing beyond that (requiring me to externally kill the process); Yahoo would not even accept the login. So, I created a new profile with no add-ons (which works fine on both those sites) and I'm gradually re-introducing add-ons to that profile, to see which one "breaks" them. OR... is there perhaps a "Do Not Use" list somewhere, already, documenting which add-on versions are known to NOT work with specific Firefox releases? Last but not least... 4. Would there be any value in running the broken Firefox 33 profile, and sending you the "Troubleshooting information" via the link below?