ToxicPlay 404 means that your forum is not online (e. g.: was archived, likely due to inactivity). Since the format of that backup changed too, I will need to create a legacy script that can restore old backups. However, I've restored your forum manually for now, so it should be accessible now.
ToxicPlay thanks for the answer, but I can't enter the settings that way... wrong ID
What ID have you entered? A valid ID is either your forum tag, hostname or the E-mail that you used during signup. FYI your forum tag is
toxicplay (part before .freeflarum.com)
Is your forum accessible now? Fixing up your forum doesn't reactivate forums, nor obtains a SSL certificate, so there was probably a different issue