$mech->selector('.tableSearchResults')?
Also note that the first argument to ##
use strict;
use warnings;
use WWW::Mechanize::Firefox;
my $mech= WWW::Mechanize::Firefox->new();
$mech->get('http://jobs.scotiabank.com/search/advanced-search/ASCategory/IT/ASPostedDate/-1/ASCountry/Canada/ASState/Ontario/ASCity/Toronto/ASLocation/-1/ASCompanyName/-1/ASCustom1/-1/ASCustom2/-1/ASCustom3/-1/ASCustom4/-1/ASCustom5/-1/ASIsRadius/false/ASCityStateZipcode/-1/ASDistance/-1/ASLatitude/-1/ASLongitude/-1/ASDistanceType/-1');
my $id="search_result_next_page_link";
$mech->click({ xpath => qq{//*[\@id="$id"]}, synchronize => 0 });
sleep 2;
my @tt= $mech->xpathEx(xpath=>'/html/body/form/div[4]/div/main/div/div[3]/section/div/div/table/');
print 0+@tt;
print $tt[0]->{innerHTML};
print "\n<--- bad API usage\n";
@tt= $mech->xpathEx('/html/body/form/div[4]/div/main/div/div[3]/section/div/div/table');
print 0+@tt;
print $tt[0]->{innerHTML};
print "\n<--- fixed XPath\n";
@tt= $mech->selector('.tableSearchResults');
print 0+@tt;
print $tt[0]->{innerHTML};
print "\n<--- CSS\n";