DBD::mysql::st execute failed: Duplicate entry 'O' for key 'itembarcodeidx' at /usr/share/koha/lib/C4/Items.pm line 2171. addorderiso2709.pl: DBD::mysql::st execute failed: Column 'itemnumber' cannot be null at /usr/local/share/perl/5.10.1/DBIx/Class/Storage/DBI.pm line 1834. DBIx::Class::Storage::DBI::_dbh_execute(): Column 'itemnumber' cannot be null at /usr/share/koha/lib/Koha/Acquisition/Order.pm line 65 (Where "O" was the duplicate barcode in question)
It looks like tricky to fix. Do you have an idea on how to fix it correctly?