Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prŏbātōrĭa, ae, f. (sc. epistula) [id.], a letter of recommendation (from the emperor), a certificate of qualification (postclass.): sacra probatoria, Cod. Just. 12, 58, 2: emissa sacri scrinii probatoria, ib. 12, 60, 6; 12, 36, 7.