Hey there!
Hard to say what exactly went wrong there, but someone on the Discord had a similar error earlier. The solution for him was to unpack the game into a fresh location/folder and then launch it from there (i.e. not use the update-only patch). Give that a try and see if it works.
Alternatively, you could check the autosaves. They should still work, and there should be one from the end of last update in there.
If neither of these things work, let me know and we'll see what we can do. I'll check back in here in a bit, to see if you've replied. Or, you could join the Discord and see if you catch me there. Gonna be on there for a bit longer before I head off for the day.
(And even if I'm not on, there might be others there who can help you when you post in the bug-reports channel)