Nucleotide BLAST database './nt ' does not exist in the NCBI servers

Why do I get this error - "Nucleotide BLAST database './nt' does not exist in the NCBI servers" - when running the code below? The stack trace is pasted below the code. Thank you.

#!/usr/bin/perl -w
use strict;
use Bio::Tools::Run::StandAloneBlastPlus;
use Bio::Seq;

my $fac = Bio::Tools::Run::StandAloneBlastPlus->new(-db_name => 'nt', -remote => 1);
my $seq_obj = Bio::Seq->new(-id  =>"test query", -seq =>"TTTAAATATATTTTGAAGTATAGATTATATGTT");
my $result = $fac->blastn(-query => $seq_obj);




------------- EXCEPTION: Bio::Root::Exception -------------
MSG: /usr/local/blast+/bin/blastn call crashed: There was a problem running /usr
/local/blast+/bin/blastn : BLAST Database error: Nucleotide BLAST database './nt
' does not exist in the NCBI servers

STACK: Error::throw
STACK: Bio::Root::Root::throw /home/lupey/downloads/bioperl/bioperl-live/Bio/Roo
t/Root.pm:472
STACK: Bio::Tools::Run::WrapperBase::_run /home/lupey/downloads/bioperl/bioperl-
live/Bio/Tools/Run/WrapperBase/CommandExts.pm:1012
STACK: Bio::Tools::Run::StandAloneBlastPlus::AUTOLOAD /home/lupey/downloads/biop
erl/bioperl-run/lib/Bio/Tools/Run/StandAloneBlastPlus.pm:1303
STACK: Bio::Tools::Run::StandAloneBlastPlus::run /home/lupey/downloads/bioperl/b
ioperl-run/lib/Bio/Tools/Run/StandAloneBlastPlus/BlastMethods.pm:264
STACK: Bio::Tools::Run::StandAloneBlastPlus::AUTOLOAD /home/lupey/downloads/biop
erl/bioperl-run/lib/Bio/Tools/Run/StandAloneBlastPlus.pm:1301
STACK: ./myblastplus.pl:10
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