You are a champion, I've never used "configure" in a library before and I assumed it handled in the function not a global config item. Thanks so much.

MP3::Tag->config(write_v24 => 1);
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fixed it and it ran perfectly. full code now is:

#!/usr/bin/perl
use strict;
use warnings;
use MP3::Tag;
MP3::Tag->config(write_v24 => 1);

$mp3->title_set('new title');
$mp3->update_tags();
$mp3 = MP3::Tag->new($file);
($title, $track, $artist, $album, $comment, $year, $genre) = $mp3->aut
+oinfo();
print("$title, $track, $artist, $album, $comment, $year, $genre\n");
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