Robbbert wrote on Today, 06:38:
And, the few extensions I use (ublock origin and new tab) work fine. The only machine to give issues is a Win7 evaluation build which can run firefox 88 as the latest version, and the other day it kicked out ublock origin. Haven't figured out how to get around that yet.
Last March a root certificate used on Firefox expired which caused almost all extensions to be rejected.
If you use Firefox ESR or other unofficial forks built after that point, chances are the root certificates have already been updated to address the issue. IIRC current MyPal 68 builds (mainly for WinXP) are not affected.
TBH this has set a dangerous precedent I've never really considered before. Pretty much every certificate issued has an expiration date that will inevitably be reached, and by that point the affected software (or last major versions with support of a certain Windows version) may have long gone out of official support which means breakage that vendors may not be willing or able to address.
Robbbert wrote on Today, 06:38:
Keeping certificates up to date manually is a must on unsupported systems. I've updated certs on all my old machines, even on win9x and NT4.
The aforementioned certificate affected only one scope that is Firefox Extensions. Sadly the only way to resolve this problem is install a newer build that had the certificate updated, usually a new Firefox release after version 128, or a custom source build compiled with updated certificates.
I think root certificates can still be updated on WinXP, as is being done by some unofficial compilations. Not sure about older Windows like 9x or NT but their core functionality may not really depend on certificates as much as newer Windows. Driver signing, for instance, existed at least since WinXP but it was only since Vista that it became mandatory.