+1 to this topic. Same alpha build. No mods.
I was half-way through a new world when this bug hit upon loading up the game one morning. I do not know if there has been a recent update (maybe Alpha 24.6 Now on Steam Unstable – Stonehearth did it) but this now happens in every new game too.
Tried cancelling and replacing the blueprint, re-promoting carpenter and masons, loading and unloading, starting a new game, and even uninstalling to see if it’s some cached error.