[Koha] diacritics and arabic not appear in z39 search

hi alli have 3.8.6 installationwhen i'm searching with z39.50 client the diacritics and Arabic characters doesn't appear correctit appear like thisArba�ah Fabr�ayir 1942 f�i t�ar�ikh Mi�sr al-siy�as�iany one face this problem before i think it related with Unicode characters and marc 8 Mohamed El Zalabany Integrated library systems consultant LibroTech for library systems and information technology http://www.librotech.net mh_zalabany@hotmail.com Mobile: 0009989496