Specifically: Can't use an undefined value as an ARRAY reference at /home/koha/koha.prod/C4/Patroncards/Patroncard.pm line 86. This is caused by testing for text at line 87 rather than line 85. A patch is forth coming to fix this.
Pull request submitted. Patch is available here: http://git.koha-community.org/gitweb/?p=wip/koha-fbc.git;a=commit;h=a51ca36ea9130fe8ba52e8e2c42a25bf75d21106