addons.mozilla.org won't install add-ons, asks for a newer version of Firefox (it says I'm using 36.0), even though I have the latest version (59.0.2).
El Capitan (10.11.6), Firefox 59.0.2
addons.mozilla.org won't install this add-on (https://addons.mozilla.org/en-US/firefox/addon/anonymox/?src=search), asks for a newer version of Firefox (it says I'm using 36.0), even though I have the latest version (59.0.2). Switching "privacy.resistFingerprinting" to "true" has no effect, except that addons.mozilla.org now sees it as 52.0 (I still need 56.0 or higher).
Wubrane rozwězanje
Your useragent in your More System Details on right of post. Mozilla/5.0 (Windows NT 6.3; WOW64; rv:36.0) Gecko/20100101 Firefox/36.0
https://support.mozilla.org/en-US/kb/how-reset-default-user-agent-firefox
Either you have both 36.0.x and 59.0.2 installed and started up 36.0.x or your useragent was modified in some way either manually or by a useragent switcher extension for example.
Toś to wótegrono w konteksće cytaś 👍 1Wšykne wótegrona (2)
Wubrane rozwězanje
Your useragent in your More System Details on right of post. Mozilla/5.0 (Windows NT 6.3; WOW64; rv:36.0) Gecko/20100101 Firefox/36.0
https://support.mozilla.org/en-US/kb/how-reset-default-user-agent-firefox
Either you have both 36.0.x and 59.0.2 installed and started up 36.0.x or your useragent was modified in some way either manually or by a useragent switcher extension for example.
Since you state that toggling "privacy.resistFingerprinting" has effect, it is very likely that you have a stuck user agent and need to reset general.useragent.override via the right-click context menu to the default value as stated in the above mentioned article.
Best if to leave resist fingerprinting disabled to avoid issues with websites like in this case with the Add-ons website. I think that there is a bug to blacklist the Add-ons website to disable spoofing the user agent in this case.