What is the ruling on Hajj if menstruation occurred on the Day of 'Arafah and no one was informed of it, then the Farewell Tawaf was performed in a state of impurity? And is the Hajj considered valid and accepted in this case?

Menstruation does not affect the state of Ihram, but it prevents circumambulation (Tawaf) until purity is achieved. The Tawaf al-Ifadah is a pillar [of Hajj] that begins after the middle of the night of Nahar (10th of Dhul-Hijjah). It is permissible to delay it and combine it with the Farewell Tawaf with a single intention, but it is not valid for a menstruating woman. If a woman menstruates after 'Arafah and has not performed Tawaf al-Ifadah except while she is menstruating, then her Tawaf is invalid, and she must perform it. Her husband is not permitted to have intercourse with her until she performs the Tawaf. A menstruating woman is not required to perform the Farewell Tawaf. Intercourse out of ignorance of the ruling incurs no consequence, but it is not permissible in the future until the Hajj is completed.