I know this problem with the scoreboard was fixed (by going back to an old version)... but I wanted to update on my initial problem which broke Firefox.
I believe my issue was due to this
(22780) team. He would only show up in my scoreboard on Friday's (Private League). He doesn't show up in my Schedule this week. Everything works.
Could a simple issue like an apostrophe in the full name cause such a problem? I don't know... but my guess is yes.