As others have stated,  if the hunt mission doesnt specify a zone, then you can complete it while inside a mission.  The problem comes from the hunt missions that immediately start a door mission without having you return to contact.  This attempts to generate a mission door inside the current map,  which leaves you stranded when you attempt the mission later.
 
	 
 
	Id suggest a 're-generate mission door' be added to the game along side the autocomplete option,  but i dont know if thats even possible with the games code.