It's a very edge case, but I figured out that the game crashes going from Day 79 to Day 80 (and getting the payday notification) while selecting Crate to leave the Old Mine dungeon. Waiting for Day 80 to tick over before selecting Crate solved the issue.
Possibly related, there's a redundant Next button that appears on the 1 slot once the dungeon is finished. Attached screenshots of both.TypeError: t.props.buttons[e].func is not a function
at doClick (file:///C:/Program%20Files%20(x86)/Steam/steamapps/common/Corruption%20of%20Champions%20II/resources/app/826.d2d3bd1a8460a3bf515e.js:1:38154)
at l (file:///C:/Program%20Files%20(x86)/Steam/steamapps/common/Corruption%20of%20Champions%20II/resources/app/583.6f4a41de541d10414372.js:1:3331756)