[Koha] error with z39.50

Hello, sorry for asking another question We ran into another error this time with z39.50. We added several servers but when trying to use this service we get the following error. Unsupported UNIMARC character encoding [] for XML output for UNIMARC; 100$a -> at /usr/share/perl5/MARC/File/XML.pm line 568. For help, please send mail to the webmaster ([no address given]), giving this error message and the time and date of the error. Any help will be greatly appreciated!