Huh?Most likely, this has already happened, but I think it is not right. How can you offer wing missions in solo mode ?
As for the tricks, it is very simple. Once you are in PG or open game took such a mission and it is present in transactions, you can not enter the solo game.
By analogy with the fact that as long as you have a load you can not change the ship until it is unloaded or the new ship does not have the right place.
Thank you.