Is it obligatory to make up for past prayers in which one's 'awrah was exposed and there were errors in reciting Al-Fatihah?

Concealing the 'awrah (intimate parts) and reciting Al-Fatihah are conditions and pillars for the validity of prayer. Therefore, whoever fails to observe them out of ignorance incurs no sin, nor is he required to make up past prayers. This is similar to how the Prophet, peace and blessings be upon him, did not command the one who prayed incorrectly to make up past prayers, and Umar was not commanded to make up the prayers he missed due to janabah (definition) (ritual impurity requiring ghusl (definition)) before he learned about tayammum (definition) (dry ablution).