Can't use an undefined value as a symbol reference - perl

Question

I'm trying to use an API for a Palo Alto Networks software. The code is supposed to submit username and ipaddress of user network logins to a web interface.
When I try using PANs' API with their sample code for a windows machine the following exception is thrown:
Can't use an undefined value as a symbol reference at
C:/Perl/lib/PAN/API.pm line 179 (#1)
PAN::API::UID::login('PAN::API::UID=HASH(0x7fd113828598)', 'SCU-DSM22/pmmertens', 172.16.6.117) called at API_events.pl line 12
This is the code-example that comes with the API documentation:
#!/usr/bin/perl -w
use strict;
use PAN::API;
my $useridagent = '10.0.0.99'; #I changed this to our PAN server address
my $useridapi = PAN::API::UID->new($useridagent);
my $user = $ENV{USERDOMAIN}.'/'.$ENV{USERNAME};
my $ipaddress = unpack('W4',gethostbyname($ENV{COMPUTERNAME}));
$useridapi->login($user,$ipaddress);
I've ensure that all variables are retrieved correctly. Substituting literal values did not help either. Googling this error turned up references about hard and soft references but I don't see any infractions of these rules in the code below.
This is the codeblock from PAN/Api.pm. Line 179 is where the print starts.
sub submit () {
my $self = shift;
use IO::Socket::INET;
use IO::Socket::SSL;
my $socket = IO::Socket::INET->new(PeerAddr => $self->{server},
PeerPort => $self->{port},
Proto => 'tcp');
my $socketssl = IO::Socket::SSL->start_SSL( $socket,
SSL_version =>'TLSv1');
print $socketssl $self->xml;
$socketssl->close;
$socketssl->stop_SSL;
}

Answer 1

Both the IO::Socket::INET and IO::Socket::SSL lines should have error checking. Something like:
my $socket = IO::Socket::INET->new(....)
or die "Failed to create socket: $!"
And:
my $socketssl = IO::Socket::SSL->start_SSL(...)
or die "Failed to start SSL: ".IO::Socket::SSL::errstr();
Although instead of die I might go with Carp::confess.