The Nizari Ismailis have always maintained that the Imamah (also known as 'Imamat') can only be inherited from the current Imam to a direct descendant in a father-to-son (or grandson) hereditary lineage starting with Imam Ali and then to Imam Hussain and so on until their present and living 49th Imam, Prince Karim al-Husayni Aga Khan IV.
In Shi'a theology, the belief is that the Ahl al-Bayt, including Muhammad, his daughter Fatima Zahra and Shi'a Imams are all infallible and do not make mistakes.
According to Nizaris, they believe the Imamah continues.
Question: Do Nizari Ismaili Shias believe in the infallibility of all the Imams?
As stated above, Shias believe that their Imams are infallible. Do Nizaris believe in infallibility and if they do so they believe in the infallibility of all the Imams, including the present Aga Khan?