I'm in the Free Huron string, but here's the problem: I am currently assigned to find a pirate ship in the Yelts system, but it is never there. This may have something to do with the fact that Yelts system is currently uninhabited, as Gorky was destroyed in a mission string I did previously. This mission can't be aborted.
This is a relatively simple fix in Mission Computer. You need to find the mission string (#191) and switch the system from the old Yelts (#181) to the new empty one (#434).