There's no reason for local software to stop working when a remote server is unavailable, reconfigured, neglected, or your clock is wrong. They are doomed if they think this is sustainable.
It was a time bomb to disable functionality after a certain date and should never have been there in the first place. The decision to silently disable the override in about:config is just more evidence of how sick this it. This is not software empowering the user. This is software assuming the user is a moron who may break it.