Hello, I'm attempting to upgrade from Koha version 3.2 to version 3.6 by just copying over 3.2 db into a new instance of Koha 3.6. The webinstaller ran just fine in bringing the db up to date, bar some errors about duplicate fields that are already in the tables. However, I received these errors when I ran "remove_items_from_biblioitems.pl" script, which produces the following output: "...................................................... Use of uninitialized value $biblioitem_tag in numeric ne (!=) at /home/koha/kohaclone/C4/Biblio.pm line 3184. Use of uninitialized value $biblio_tag in numeric ne (!=) at /home/koha/kohaclone/C4/Biblio.pm line 3184. Use of uninitialized value $biblio_subfield in string at /home/koha/kohaclone/C4/Biblio.pm line 3216. Use of uninitialized value $biblioitem_subfield in string at /home/koha/kohaclone/C4/Biblio.pm line 3216. Tag "" is not a valid tag. at /home/koha/kohaclone/C4/Biblio.pm line 3216" Any help on how to solve this problem so that I can proceed with the upgrade is very appreciated.