The same thing happend to me on SUNDAY, 26/1, so it's probably just the end of the demo
Hm, actually this demo ends on 15th February, so that shouldn't happen.
Did you do any particular thing the night before? (During my playtesting, I experience that too, but it happened so randomly I couldn't find the cause.)
I had the same thing happen to me on the 26 day of January too!
and when i exited out and tried to play again i ended up geting this error page :(