my $attr_value;
my $twig2= XML::Twig->new(    
        twig_handlers => { 
                'Parameter' => sub { 
                        
                        my $attr_value = $_->{'att'}->{'value'}; 
                        print $FhResult $attr_value . ","; #Hier ist die Zeile 54
                },
        },
);

print $FhResult( (split('_', "\n$file2",2))[0] . ',' ); 
$twig2->parsefile($file2);