[Exim] Perl and 4.10

What is the meaning of

2002-12-03 11:04:16 18J9uZ-0000uu-00 Error in system filter: failed to
expand
"${perl{amavis_filter_scan}{$message_id}{$sender_address}{$recipients}}"
in filter file: Perl subroutine "amavis_filter_scan" returned undef to
force failure

Im trying to get amavis-ng to work with embedded perl.

The called script is

nvoweb:/usr/share/amavis# cat amavis-filter
# $Id: amavis-filter,v 1.7 2002/07/18 22:33:36 bengen Exp $

#
# Main file for the Embedded Perl version of AMAVIS
#

use AMAVIS;
use strict;

use vars qw/$returncode $returntext $args $amavis/;

# Main routine that is called from Exim system filter
sub amavis_filter_scan {
$$args{'eximperl_mid'} = shift;
$$args{'sender'} = shift;
@{$$args{'recipients'}} = split /, +/,shift;

AMAVIS->init($args);
AMAVIS->process_message($args);
AMAVIS->cleanup($args);

# Pass control back to the system filter.
return $$args{'eximperl_returncode'};
}

# Returns
sub amavis_filter_result() {
  return (defined $$args{'eximperl_returncode'} ?
          $$args{'eximperl_returncode'} :
          'unknown');
}

# # Returns text to be put into freeze message
# sub amavis_filter_text() {
#   if (defined $returntext) {
#     return $returntext
#   }
#   else {
#     return '';
#   }
# }

# Returns scanners list for X-Scanned header
sub amavis_virus_scanner_list() {
return join(', ', @{$$args{'virus_scanners'}});
}

# Returns headers to be included by system filter
sub amavis_headers() {
return join(', ', @{$$args{'headers'}});
}

1;
nvoweb:/usr/share/amavis#