take a look at the perldoc for the modules and try to follow their examples.

my $ldap = Net::LDAPS->new( 'hostname' ) or die "$@";
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then you might get an error message that tells you what's wrong with your code.

and it is a bit deep in the docs, but you can try this:

my $ldap = Net::LDAPS->new( 'hostname', verify => 'none' )
  or die "$@";
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or even

my $ldap = Net::LDAP->new( 'myhost.example.com', version => 3 );
my $mesg = $ldap->start_tls(
                           verify => 'require',
                           clientcert => 'mycert.pem',
                           clientkey => 'mykey.pem',
                           decryptkey => sub { 'secret'; },
                           capath => '/usr/local/cacerts/'
                         );
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the other possibility is that the UNIX system is missing IO::Socket::SSL and/or the openssl libraries that these modules use. getting error messages will help you find out what's happening.