Can't join SkyFactory4 server

I have a skyfactory 4 server that I've been playing on. I tried to log on today, but when I tried to join, it stopped at "Logging in" and gave me an error. The error was "Failed to login:null". I've been playing on the normal minecraft launcher (the minecraft launcher is launched through curseforge). If anymore info would help you, just ask me and I'll respond. Please help, I don't want to lose all of my progress.

Yes. I figured out how to fix it though. I had to turn on the "cracked" setting in options. I lost all of the stuff on my player, but the world was fine.