playing Harvest Festival Legacy

My game crashed once and now all the NPCs are frozen in place and Yulif has disappeared. I've tried leaving the world and coming back but nothing has changed. Animals still move and I can still talk to the NPCs

If Yulif has vanished. you can simply put him back. Go into Creative Mode, and search the creative menu for "Yulif". Grab that and simply place it on the ground to spawn a new one.

If you are in Single-Player, and are unable to use the /gamemode command, simply press Escape, click 'Open to LAN' and enable cheats - you will then be able to use the command.

Note that there is also the option to grab a new Carpenter Building by giving more logs to the Harvest Goddess, and you can remove the old building.