Can't call method "desiredCompressionLevel" on  
an undefined value at C:/aaa/perl/site/lib/Archive/Zip/Archive.pm line 249.

Notes: 
$dir = "absolutepathto/foldername"; 
-------------------------------------- 
use Archive::Zip; 
use File::Find; 
use File::Spec::Functions qw(abs2rel); 
 ($dir, $flatten) = @_; 
 die "Invalid parameter $dir" unless -e $dir && -d $dir; 
 $zip = Archive::Zip->new(); 
 find ( sub { 
  $name = $flatten ? $_ : abs2rel($File::Find::name, $dir); 
  $zip->addFile($File::Find::name, $name); 
 }, $dir); 
 if ( 
 $zip->writeToFileNamed("foldername.zip"), 
 ) { 
  print qq ~<div align="center">Error cannot create backup!~; 
 } else { 
  print qq ~<b>($zipname)</b> has been zipped up</div>~; 
  }