If for some reason you're still using a version of Firefox, or one of its forks like R3dfox, LibreWolf, etc, older than version ESR 115.13 or version 128 then you will have to update because of a root certificate expiration on 14 March 2025 which may cause significant issues with add-ons, content signing and DRM-protected media playback.
Mozilla page about this:
https://support.mozilla.org/en-US/kb/root-certificate-expiration
Discussion and more info:
https://support.mozilla.org/en-US/questions/1468274