This bug is quite similar to Bug 12638. I insert hellenic chars in frequencies and in numbering patterns I use a bibliographic record with hellenic chars in title. I create a subscription with this biblio and with frequencie and numbering pattern with hellenic char. I try to do a search with ISSN of the biblio (0154-8344). The result is: Software error: Template process failed: undef error - Undefined subroutine &Koha::Template::Plugin::AuthorisedValues::encode called at /home/koha/src/Koha/Template/Plugin/AuthorisedValues.pm line 28. I use sandbox n.6
This is fixed by the last patch set submitted by Dobrica. I will update the sandboxes today.