Mistake of law arises when known facts are misinterpreted legally rather than from factual ignorance. A mistake is an error, misconception or misunderstanding about facts material to a contract, arising from ignorance, surprise, imposition, misplaced confidence, omission or similar causes. A mistake of law occurs when a person with full knowledge of the facts reaches an erroneous conclusion as to their legal effect, i.e., an error concerning the legal consequences of known facts rather than the factual premises themselves.