Kiln is opening and closing repeatedly. It's set to make ceramic. It contains 75 kg of coal. I have clay available but the kiln is low priority.
15 second video taken on cellphone (sorry, I'm dumb when it comes to screen capturing software):
Save file is attached, but reloading does resolve the issue (ie, save file probably won't be of any use).
No clue, sorry for the head scratcher. You should find the video entertaining though :)