Does ignorance of a mistake invalidate the prayer, and necessitate its making up when one becomes aware of it later?

If the error is something that invalidates the prayer, such as omitting a pillar (rukn) thereof, then if it was intentional, the prayer is nullified by the consensus of jurists. If it was omitted out of ignorance or forgetfulness, then it must be performed if it is possible to rectify it. Otherwise, the rak'ah (unit of prayer) from which the pillar was omitted becomes invalid, and the subsequent rak'ah takes its place. This applies if the omitted pillar is not the intention (niyyah) or the opening takbir (takbirat al-ihram). As for one who omits the intention or the opening takbir, he must restart the prayer because he has not fundamentally entered into it. Also, repetition of the prayer is obligatory for one who prayed without ablution (wudu) or while in a state of major ritual impurity (janabah) while having access to water and being able to use it. Sheikh al-Islam Ibn Taymiyyah held the view that one who omitted a condition (shart) or a pillar out of ignorance is not obligated to make up the prayer, but rather to repeat the prayer of that specific time. The view of the majority (jumhur) is more cautious and more absolving of responsibility.