Getting "500 Internal Server Error" retrieving page with LWP::UserAgent - perl

Question

I'm trying to retrieve a page using LWP::UserAgent but I keep getting a "500 Internal Server Error" as a response. Retrieving the exact same page in Firefox (using a fresh "Private Window" - so without any cookies set yet) succeeds without a problem.
I've duplicated the headers exactly as sent by Firefox, but that still does not make a difference. Here's my full code:
use strict;
use LWP::UserAgent;
my $browserObj = LWP::UserAgent->new();
$browserObj->cookie_jar( {} );
$browserObj->timeout(600);
my #header = (
'Host' => 'www.somedomain.com',
'User-Agent' => 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0',
'Accept-Language' => 'en-US,en;q=0.5',
'Accept' => 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'Accept-Encoding' => 'gzip, deflate, br',
'DNT' => '1',
'Connection' => 'keep-alive',
'Upgrade-Insecure-Requests' => '1'
);
my $URL = "https://www.somedomain.com";
my $response = $browserObj->get( $URL, #header );
if( $response->is_success ) {
print "Success!\n";
} else {
print "Error: " . $response->status_line . ".\n" );
}
The real web address is something other than "www.somedomain.com". In fact, it's a URL to an online casino, but I don't want my question be regarded as spam.
But anyone any idea what could be wrong?

Answer 1

On our corporate network which has a proxy (and an out of date perl version - there may be better options in newer versions) we tend to add the following for one-offs:
BEGIN {
$ENV{HTTPS_DEBUG} = 1; # optional but can help if you get a response
$ENV{HTTPS_PROXY} = 'https://proxy.server.here.net:8080';
}
If we don't do this the script simply fails to connect with no other information.
You may also want to add something like this if you want to inspect the messages:
$browserObj->add_handler("request_send", sub { shift->dump; return });
$browserObj->add_handler("response_done", sub { shift->dump; return });