[Koha] KOha errro Z3950 Search

Hello. I am trying search z3950 ,but returns no results. At errorlog apche we get the message DBD::mysql::st execute failed: You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1 at /usr/local/koha/intranet/modules/C4/Breeding.pm line 168. DBD::mysql::st fetchrow_hashref failed: fetch() without execute() at /usr/local/koha/intranet/modules/C4/Breeding.pm line 169. query=Select id,file,isbn,title,author from marc_breeding where title= isbn= at /usr/local/koha/intranet/modules/C4/Breeding.pm line 167 Who could help me.. Thanks. --