I’ve just gotten the same error when trying to load March to October. I haven’t played it in a month or so. I’ll try to reboot as you said. Side note, I’m so annoyed with how finicky this game is about being connected to the network.
Update: Restarting the console did not work. Sigh. The save file is there (I last saved it 4/24/22) but won’t load. So annoying.