RTFM 2.0.4: Associating custom fields with classes

Hi all,
I am running RTFM 2.0.4 and I have the following problem when I try to
associate a Custom field (type TextSingle) to a class:

System error
error: Can’t locate object method “HasEntry” via package
"RT::CustomFields" at
/usr/share/request-tracker3.4/html/RTFM/Admin/Classes/CustomFields.html
line 86.
context:
82: # Go through and delete all the custom field relationships that
this class 83: # no longer has 84:
85:
86: if ($ClassCFs->HasEntry($cf->Id)) { 87: unless (defined
$ARGS{“Class-”.$ClassObj->Id."-CF-".$cf->Id} ) { 88: my ($val, $msg) =
$cf->RemoveFromClass($ClassObj->Id); 89: push (@results, $msg); 90:

code stack: /usr/share/request-tracker3.4
/html/RTFM/Admin/Classes/CustomFields.html:86
/usr/share/request-tracker3.4/html/autohandler:215
I have added use RT::CustomFields but I have no sucess

use RT::FM::Class;
use RT::FM::CustomFieldCollection;
use RT::FM::ClassCustomField;
use RT::CustomField;

my $ClassObj = new RT::FM::Class( $session{‘CurrentUser’} );
my ( $title, @results );
$ClassObj->Load($ARGS{‘id’}) || $m->comp("/RTFM/Elements/Error", Why =>
“Couldn’t load class ‘$id’”);
my $ClassCFs = $ClassObj->CustomFields;
my $CustomFields = RT::FM::CustomFieldCollection->new(
$session{‘CurrentUser’} );
$CustomFields->UnLimit;
$title = loc( ‘Edit Custom Fields for Class [_1]’, $ClassObj->Name );

if ($ARGS{‘UpdateCFs’} ) {
while (my $cf = $CustomFields->Next) {
# Go through and delete all the custom field relationships that this
class
# no longer has

if ($ClassCFs->HasEntry($cf->Id)) {
unless (defined $ARGS{“Class-”.$ClassObj->Id."-CF-".$cf->Id} ) {
my ($val, $msg) = $cf->RemoveFromClass($ClassObj->Id);
push (@results, $msg);

Can anyone help me?
Thanks in advance
Best Regards
Teresa