For whatever reason, the new Firefox 57 is being identified as Epiphany 3. I found this at https://www.whatbrowser.org/. Normally, this wouldn't be much of an issue, but this prevents a lot of the interactive functionality for extensions at mozilla's website. I am using ubuntu 17.10 and have downloaded the latest version of firefox from the update prompt this past week. I disabled all of my extensions as part of this troubleshooting process, but that did not seem to resolve anything.