use XML::Simple;
my $xs = XML::Simple->new();
my $ref = $xs->XMLin('test.xml');

for my $mandant (@{$ref->{Company}}) 
{
print $mandant->{ID}."\n";
print $mandant->{Name}."\n";
}               

<?xml version="1.0" encoding="UTF-8"?>
<License xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Company>
    <ID>100</ID>
    <Name>Mandant 1</Name>
  </Company>
  <Company>
    <ID>110</ID>
    <Name>Mandant 2</Name>
  </Company>
</License>

 error:Not an ARRAY reference