Impossibilities, obstacles, hindrances, barriers, blockades, limitations, handicaps, deficiencies, restrictions, prohibitions, denials, difficulties, setbacks, impenetrable walls, impasse, standstill, stalemate, dead ends, restrictions, interdictions, disabilities, encumbrances, inabilities, disabilities, inabilities, insufficiencies, inadequacies, defects, flaws, weaknesses, shortcomings, inefficiencies, ineptitudes, incapacities, shortcomings, drawbacks, complications, complexities, intricacies, challenges, obstructions, handicaps. All of these words can be used as synonyms for the word "impassibilities".