False alarm, not a bug
Edit: found out to be a false alarm and not a bug after all.
Original post:
I think this is an old bug, as I remember I had this issue in previous builds, but still worth mentioning: I'm playing a huge map, clearing out the AI one by one, when suddenly I can't build any orbital structures in the conquered planets. The construction ships cruise to the build location and then either the build bar doesn't move at all, or the construction ships just leave the orbital building halfway built, refuse to keep building it even when directed to it manually and the whole thing grinds to a halt, nothing is being built by my constructors (starbases build up just fine).
Currently, I'm playing as Vasari Loyalists and researched hastened building speed for orbital structures. Would love to provide further detail and a savegame, although I'm not sure where is it located, even checked the appdata\local and there's no Ironclad or Sins directory there. I'm on Win 8 64 bit.