I'm using the build tool to place my town hall block, I've made sure the preview is aligned with the flat, unobstructed area I'm trying to build it on. When I click the green checkmark, it only places the town hall block floating in the air where it would appear in the contructed Dark Oak Town Hall. But none of the tree or other structure appear, just the floating town hall block. I earned the "start a colony" achievement or whatever it's called, but there's no town hall! Just a floating lectern.

I'm running a server and in the log the most relevant message I can find it "Buildtool: building is null!"

What could be causing this? I really want to enjoy Craft to Exile...