so, my harddisk was on it's way out, was making a clicking noise but functioned well. so I decided to try to ghost it to a new harddisk, that failed because a readwrite head musta been busted. sigh. so I got a new copy of windows 7 installed and then needed to reinstall all my software.

Firefox 51.0 is the last firefox that you can stop from updating that allows flashplayer.

flashplayer was fairly easy to install. albeit I have unbricked 32 instead of 31 set to version 33 like before (to disable the "outdated plugin" message)

but all my other precious addons were no longer available! luckily I had a backup computer with all the .xpi files and a working firefox 51.0 installation so I could copy some files over, and if you get an xpi you too can install it in an old firefox by the following:

in firefox, go to about:config and search for "xpi" then toggle xpinstall.signatures.required to false.

you might need to create a folder called "extensions" in "C:/Users/yourusername/AppData/Roaming/Mozilla/Fi refox/Profiles/yourprofile.default/" in this extensions folder insert your .xpi files.

now in C:/Users/yourusername/AppData/Roaming/Mozilla/Fir efox/Profiles/yourprofile.default/ you need to modify the addons.json and addonStartup.json.lz4

what you don't have addonStartup.json.lz4? you'll need to copy it from an older ff51 install that includes the addons. if you don't have that it is a binary file so I can't help. you could try without it and see if it auto generates this file on browser restart after accepting addons you installed this way.

when you open firefox after this, it will open tabs asking if you want to accept the addon, check the box and accept. congrats your old addon works.

some addons like adblockerultimate may force you to update that one addon before the browser stops disabling it. but things like downthemall the download manager, or advanced cookie manager and older versions of noscript install this way just fine.

It is in most regards just like the old pre-modern version of firefox, only that it gets modern security fixes and not as much broken web compatibility. Like, if it doesn't work anymore on old firefox it will never work again, but on palemoon updates regularely recover lost chromeshit pajeet code websites to work properly again. That's the reason I switched from my firefox installation.

There was basilisk also which is the same thing only with a modern interface like current year firefoxes, if that's more your thing, but I'm not sure if that one wasn't discontinued not too long ago.

but yeah if palemoon allows me to install advance cookie manager by jayapal then I might switch everything over to that.

Yeah, been using palemoon as my goto browser ever since the "end" of flash. Only in like 1% of cases do I need to fire up that modern firefox sitting on the bench.
Currently there was some hefty bullshit going on with cloudflare literallly gatekeeping which browsers can access the internet and palemoon obviously was none of those, so they had big problems with behind cloudflare protection websites not being able to load, but as of now that seems to work again at least. Not sure if it's temporary of finally resolved, but that was the 2nd largest wall I ever faced with palemoon, with only 1 other example. Maybe it's not as fast as a browser could be? Rarely I experience such issues though and the eventual crash with the 32-bit version (never had those with 64-bit but my PC is too old for that now). Apart from that it's been very fine, especially because you can still use flash-in-browser (on /f/ at least, wouldn't recommend enabling it everywhere). Big thanks to Ants again for the plugin edits and the many anons who researched the timebomb.

So yeah, firefox is for dummies and you're at fault if you use it and complain.
tl;dr: Don't home that chrome.

I use old noscript in FF51, Adblocker Ultimate (old version), and down them all download manager.

I used to use a user agent switcher as well, but the menu broke for it. and it glitches my addon hacking and may cause my addons to be deinstalled.

Advanced Cookie Manager allowed live deletion of specific cookies and live cookie value editing. that was fun to go into a spyware vendor (google, cloudflare etc.) cookie and change the value from whatever garbled value they set to "Cease and Desist".

oh well. I am sad I can't do that any more.