Hi I wrote a script for parsing blast output and get some of the statistics. But while I run the script:

use strict;
use warnings;
use Bio::SearchIO;
use Bio::Search::Tiling::MapTiling;

my $infile = $ARGV[0];
my $in = Bio::SearchIO->new(-format => 'blast', -file => $infile);
my $result = $in->next_result;

my $hit;
while ($hit = $result->next_hit){
        my $tiling = Bio::Search::Tiling::MapTiling->new($hit); 
                my $query_length_tiling = $tiling->length('query');
        my $sub_length_tiling = $tiling->length('subject');
        my $qid = $tiling->frac_identical('query');
        my $qcov = $tiling->percent_identity('query');
                print $query_length_tiling."\t".$sub_length_tiling."\t".$qid."\t".$qcov;
        print "\n";
        }

I am getting this error

--------------------- WARNING ---------------------
MSG: No HSPS present for type 'hit' in context 'p_' for this hit
---------------------------------------------------
Can't use an undefined value as an ARRAY reference at /Library/Perl/5.18/Bio/Search/Tiling/MapTiling.pm line 1135, <GEN1> line 600.

Please help me to resolve this error. Bioperl v1.007001 and BLAST+ 2.2.31

EDIT: Only throws this error when asking to report the methods for 'subject' or 'hit'. For 'query' only, everything works just as expected.

Thank you shyam