I am unable to reproduce your findings (if I have understood them correctly):

$ cat 11128519.pl 
use strict;
use warnings;
use MCE::Loop;
MCE::Loop->init (
    chunk_size  => 1,
    max_workers => 10,
    use_threads => 0
);
my %result;

MCE::Util::get_ncpu

  %result = mce_loop {
    my ($mce, $chunk_ref, $chunk_id) = @_;
    my %ret;
    for my $item (@{$chunk_ref}) {
        my $ret = tags_get ($item);
        $ret{$item->[1]} = $ret->{$item->[1]};

        #say $ret{$_->[1]};
    }

    $mce->gather (%ret);
}
$fileprobe;
MCE::Loop->finish;
$ perlcritic 11128519.pl
11128519.pl source OK
$ perlcritic -2 11128519.pl
Code not contained in explicit package at line 1, column 1.  Violates 
+encapsulation.  (Severity: 4)
No package-scoped "$VERSION" variable found at line 1, column 1.  See 
+page 404 of PBP.  (Severity: 2)
Module does not end with "1;" at line 26, column 1.  Must end with a r
+ecognizable true value.  (Severity: 4)
$ perlcritic --version
1.125
$
[download]

PS. Perhaps the problem lies with the code you haven't shown us (the calling code)?

Short guess: write

%result = mce_loop sub {

if you want to keep that Citric rule activated.

Long guess: mce_loop seems to be defined with a prototype (&) which treats a following code block like a sub

Critic doesn't see that and thinks the @_ is not at the right position.

Inserting an explicit sub should fix that

Disclaimer: I'm neither a user of critic nor mce, and can't test.

update

It's unlikely that Critic is always doing that, because such prototype stuff is not uncommon. The full answer is in your environnement.

For info doing this

%result = mce_loop sub {

Results in a syntax error

However wrapping the the whole thing in a sub removes the error, will have to see if it breaks the code.ie

%result = mce_loop {sub {
               my ($mce,$chunk_ref,$chunk_id) = @_;
               my %ret;
               for my $item (@{ $chunk_ref }) {
                    my $ret=tags_get($item);
                    $ret{$item->[1]}=$ret->{$item->[1]};
                    #say $ret{$_->[1]};
               }

              $mce->gather(%ret);
            }
            } $fileprobe;
[download]

thanks

did you separate the arguments behind the block with a comma after introducing "sub"?

  DB<25> sub run (&@) { my $code =shift; $code->(@_) }

  DB<26> *mce_loop = \&run

  DB<27> mce_loop {print "code @_"} 1,2,3            # no comma needed
code 1 2 3
  DB<28> mce_loop sub {print "code @_"}, 1,2,3       # comma needed
code 1 2 3
  DB<29> mce_loop sub {print "code @_"} 1,2,3        # syntax error
Number found where operator expected at (eval 38) ...
[download]

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}

> '%result = mce_loop sub {'

> Results in a syntax error

this shouldn't be, the problem must be somewhere in your code.

I looked into the code of MCE::Loop and it works like I guessed.

That's what's essentially happening in the import

  DB<8> sub run (&@) {}

  DB<9> *mce_loop = \&run

  DB<10> mce_loop {print "code"}

  DB<11> mce_loop sub {print "code"}

  DB<12> mce_loop sub {print "code"},@_

  DB<13> mce_loop 1
Type of arg 1 to main::run must be block or sub {} (not constant item)
+ at
[download]

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}