I clicked on the dice icon in the top corner and it shuffled my dock module around and added a bridge between it and the 'unknown module', which seemed a sensible idea so I confirmed the changes. Later I figured out how to assign a builder to the PHQ and went away to do some missions whilst it got on with it.
Came back a while later to find... empty space where the unknown module used to be
The station still existed on the map and the unknown module was fourth in the queue of things to be (re)built, so I guess by clicking the dice icon it must have moved the location of the unknown module and decided to deconstruct it - even it's central asteroid had vanished. The builder was just sat idle next to it.Luckily I was able to revert to an auto-save prior to the broken state, albeit at the cost of an hour of progress. I don't know if, given enough time, the builder would have successfully rebuilt it and I didn't want to risk it anyway since moving it's location even slightly might play havoc with whatever future plot events occur for the PHQ.
Partly my own fault for pressing random buttons to figure out what they do I guess, but it feels like the "core" module of the PHQ (unknown module) should be locked in place so the plot builder editor can't move it. Thought it was worth reporting so Egosoft are aware of it and could potentially add something to the editor to prevent 'accidents'
