We're sorry there's been issues with your playthrough :0. We're gonna be releasing a fixed up version of the demo in about a week. If you've got any other details you can share, please do let us know. Things like what you had been doing in the file, if it always happens or sometimes it doesn't, if an error screen pops with (and what the error screen says, if so) or if the game just stops responding, etc.
Oh I'm glad the issue went away. Still, if it ever happens again or anything else occurs feel free comment on it. We'll be happy to look into it :].