I am not sure what happened...don't think I had an event, but when I checked on my Villagers today...
- all puzzles reset to incomplete - lab, cave, bath, trees all reset to start
- all villagers/food/tech points still there - 32/4850/248975
- all technologies fully researched, nature at level 3
- awards still there
- all huts incomplete
- graveyard full
- all collections still there - 9/12, 10/12, 10/12, 12/12
- all keys reset

Left the game running overnight on slow

WHAT GIVES????
In any case...I am done. This version takes too long to make progress and I don't have the patience or motivation to re-do everything.