[Koha] z39.50 search

Problem: Z39.50 search not working! Koha 2.2.9 installed on Windows. Internal Server Error when trying to execute the Z39.50 search. If I delete that function(LOC), and only search 'amicus canada', the search returns a positive result. We have installed and uninstalled meticulously, and been super careful setting parameters. Has any-one got a solution? Thanks, Carmel