Server Failed to Start

I was playing and noticed my Cave Entrance was blocked up because the server had an error or something. I closed DST and relaunched it, but trying to load my game gives me:

I can launch older worlds and new ones so I don't have much of idea of what happened. The server log says there missing reference to a beefalo bell. I used one on a beefalo then immediately dropped it to handle other things. When I found out my Wx78 circuits made carrying things easier, I never returned to that bell. I don't think a bell left on the ground for a hundred+ days would be a problem though.