my $twig = XML::Twig->new();
print ref $twig,"\n";
$twig->parsefile("player.xml");
my $root= $twig->root;
print ref $root,"\n";

# prints:

XML::Twig
XML::Twig::Elt
[download]

It seems you are still using $root for the method call instead of $twig. If I use $root->print_to_file instead of $twig->print_to_file, I too get the error message that the function can't be found

Here is the code snippet which I am currently using

use strict;
use warnings;
use XML::Twig;
use Data::Dumper;

my $twig = XML::Twig->new(twig_roots => { name => 1});
$twig->parsefile( "player.xml");
$twig->print;
$twig->print_to_file();
[download]

Here are the outputs :
$ ./xml_twig_test.thpl Can't locate object method "print_to_file" via package "XML::Twig" at ./xml_twig_test.thpl line 22.
<stats><name>Houston, Allan</name><name>Sprewell,
Latrell</name><name>Ewing, Patrick</name><name>Johnson,
Larry</name></stats>
This is sort of weird since the other methods of XML::Twig are working fine except print_to_file() function

If I execute above script, I get an error because print_to_file needs a filename as parameter, but after adding that, all runs as expected. So maybe you have a very old twig version (mine seems to be from 2007-11-13). Is print_to_file() mentioned in the man page of Twig? Can you find the subroutine print_to_file if you simply search the file XML/Twig.pm with grep (should be somewhere in /usr/lib/perl5 if you have a normal linux distribution)

If not, just get a newer version from CPAN.