Bug 26979 added some plural handling to the labels shown in circulation. There are some additional warns that are appearing because of this in the QA test tools: Argument "" isn't numeric in subroutine entry at /usr/local/share/perl/5.24.1/Locale/Messages.pm line 285.
I am seeing Argument "" isn't numeric in numeric gt (>) at /kohadevbox/koha/koha-tmpl/intranet-tmpl/prog/en/includes/patron_messages.inc line 128. Argument "" isn't numeric in numeric gt (>) at /kohadevbox/koha/koha-tmpl/intranet-tmpl/prog/en/includes/patron_messages.inc line 128. Argument "" isn't numeric in numeric gt (>) at /kohadevbox/koha/koha-tmpl/intranet-tmpl/prog/en/modules/members/moremember.tt line 237. Argument "" isn't numeric in numeric gt (>) at /kohadevbox/koha/koha-tmpl/intranet-tmpl/prog/en/modules/members/moremember.tt line 716. but not yours. Which version of Locale::Messages are you using? % pmvers Locale::Messages 1.26