Ran into a case where duct routing could not be completed, due to missing fitting settings in a duct type. While the routing should still occur, if there's going to be an error thrown up, there should be a better warning that states "duct type is not clearly defined" instead of "no routing solution possible". Clearer explanation of these errors would help. The error can be seen here:
https://youtu.be/xhTK04cSn1M
thanks - David B.