I ran the below code -->

package Database;
use base 'DBIx::ActiveRecord::Model';
DBIx::ActiveRecord::Model->table('sca_lt'); # table name is required
DBIx::ActiveRecord::Model->columns(qw/pid fp fn/); # required
DBIx::ActiveRecord::Model->primary_keys(qw/pid/); # required

my $data_source = 'dbi:SQLite:sca_lt';
my $username = 'user';
my $auth = 'pwd';
DBIx::ActiveRecord->connect($data_source, $username, $auth, \%attr);

my $m = Database->new();

my $list = $m->all;

print $list;
[download]

Error message is as below -->

Can't call method "instantiates_by_relation" on an undefined value at at I:/Perl/site/lib/DBIx/ActiveRecord/Scope.pm line 88.