I do not think that Vatican II is a valid ecuмenical council of the Roman Catholic Church.
That being said, as I mentioned in my response to RomanTheo, the primary issue of our current crisis is not Vatican II. This council can be interpreted in a way, commensurate to the machinations that gave birth to it, that is in continuity with Tradition due to the very ambiguous nature of its docuмents which were engineered to create weaponized nebulosity.
The primary issue, rather, is that the post Vatican II “Popes,” ecclesiastical hierarchy, theologians, monastic orders, and the vast majority of the laity have apostatized completely from the Catholic faith.