It sounds like you may have merged files instead of deleting and replacing old ones. For some reason this can mess up the code. I recommend a fresh install
apparently a lot of people are catching this bug during the sleepover. I play on deck and i cant/don't know how to open the console commands after changing the file that I found out about in your discord. And I can't seem to transfer the files to my laptop to fix it that way, then return it to my deck. So I'm at a loss lol idk what to do.
Edit: I figured out how to fix it. Thanks Runey
I have the same issue, and I tried reinstalling the game.
I'm no code expert, and I don't know if I merged any files, If so I did it by accident.
I tried starting a new game and did everything again, but then got the same popup.
I did not delete my old saves though.
Might just be a bug? I did also try to not interact with kate since on my old save I went through all her riddles.