To try to eliminate potential issues, the following was ran from the command line:

test script:

#!/usr/bin/perl
use CGI qw(:standard);
use CGI qw(:standard Vars);
use CGI::Carp qw(warningsToBrowser fatalsToBrowser);
use File::Basename;
use lib dirname(__FILE__);
use CreateExam;

my $cgi = CGI->new(\*STDIN);
print $cgi->header();
print $cgi->start_html("test");

my $check = CreateExam->new("/var/www/roger/homeworks/hw13/exam4.txt",
+"/var/www/roger/homeworks/hw13/answers4.txt","/var/www/roger/homework
+s/hw13/grades4.txt",0);

my %ans;
$ans{"1"} = "0AD";
$ans{"2"} = "Johnny Manziel";
$ans{"3"} = "washington";
$ans{"4"} = "Shes so hiiiigggghhhhhh\nHigh above me\nShes so hiiiigggg
+hhhhhh above me\nCleopatra Joan of Arc Aphrooooodiiiiitttteeee\n";

print $check->entergrades("test",\%ans);
print qq(<div style="margin:10px;border:solid;border-width:10px;border
+-color:#FFFFFF">\n);
$check->printgrades("test");
print "</div>\n";
print $cgi->end_html();
[download]

CreateExam.pm:

sub new {
    my ($class,$file,$answers,$grades,$script) = @_;
    #print "<p>in new: file: $file, grades: $grades</p>\n";
    return bless {'file'=>$file,'answers'=>$answers,'gradefile'=>$grad
+es,'script'=>$script},$class;
}
....
sub entergrades {
    my ($self,$person,$answers) = @_;
    my $afile = $self->{'answers'};
    open(ANSWERS,"<$afile") or die "$afile: $!";
    my $grades = $self->{'gradefile'};
    open(GRADES,"<<$grades") or die "got error $! (".($!+0).")\n"; # p
+roblem right here
        ...
}
[download]

output:

Software error: got error No such file or directory (2)
[download]

double check file exists:

jddancks@debian-macbook:/var/www/roger/homeworks/hw13$ ls -l /var/www/
+roger/homeworks/hw13/grades4.txt
-rwxr-xr-x 1 jddancks jddancks 2095 Jan 16 16:30 /var/www/roger/homewo
+rks/hw13/grades4.txt
[download]