[Koha] acquisition error module

Thanks for your help. I was able to list older vendor. I found one more problem. When I try to search for a vendor I see the following message: Can't use an undefined value as a HASH reference at /usr/share/koha/intranet/cgi-bin/acqui/booksellers.pl line 114. I run the query suggested on this main list: mysql> SELECT basketno FROM aqbasket LEFT JOIN borrowers ON (borrowernumber) WHERE borrowers.borrowernumber IS NULL;Empty set (0.00 sec) How can I fix this problem? Thanks for your help. Massimo Plevani