Responsa for Yevamot 211:7
בת חמוה דרב פפא נפלה לפני יבם שאין הגון לה אתא לקמיה דאביי אמר ליה חלוץ לה ובכך אתה כונסה אמר ליה רב פפא לא סבר לה מר להא דאמר רבי יוחנן ואלא היכי אימא ליה
'Do you not like him then?' he asked the woman.<span class="x" onmousemove="('comment',' The sister-in-law. ');"><sup>18</sup></span> 'No', she replied. 'Submit to her halizah', [the Rabbi] said to [the levir], 'and you will thereby wed her'. After the latter had submitted to <i>halizah</i> at her hands he said to him, 'Now she is ineligible to marry you; submit again to a proper <i>halizah</i> that she may be permitted to marry a stranger'. A daughter of R. Papa's father-in-law fell to the lot of a levir who was unworthy of her.<span class="x" onmousemove="('comment',' But who insisted on contracting with her the levirate marriage. ');"><sup>19</sup></span>
Teshuvot Maharam
A. Bediabad, in this case, means after the rite was performed. Nevertheless, the aforementioned performance of the rite is invalid, for a different reason: the shoe used was sewed with flaxen thread and, therefore, was never fit for this purpose. Since, however, the levir performed an invalid rite of halitzah, neither he nor his brothers are now permitted to marry the widow. Halitzah by the same levir being the only manner of releasing her, he may be forced, by persuasion or by flagellation, to repeat the rite with the proper shoe. For now the Mitzvah revolved on him alone, and we are permitted to scourge a Jew until he perform the required Mitzvot.
This Responsum is addressed to Rabbi Menahem of Würzburg.
SOURCES: Am I, 93, 94.