What is the ruling on one from whom semen is discharged inadvertently during Ramadan? Is he obligated to fast for sixty days, and what if he is unable to fast them?

The correct view is that whoever consumes something that breaks the fast during Ramadan, whether forgetfully or out of ignorance of its ruling, is not required to make up for it (qada') nor to offer expiation (kaffarah). This is based on the Prophet, peace and blessings be upon him, who said: "If he forgets and eats or drinks, then let him complete his fast, for it was Allah who fed him and gave him drink." Ibn Hibban added: "So there is no qada' upon him, nor kaffarah." Based on this, you are not required to make up for it as long as you did not intentionally cause the discharge, and there is no kaffarah, as kaffarah is only necessitated by intentional sexual intercourse during Ramadan.