SSCCE works for me.

use strict;
use warnings;

use File::Copy 'copy';
use Test::More tests => 1;

my $longname = 'foo_' . ('z' x 200);
open my $fh, '>', $longname;
print $fh "Hello!\n";
close $fh;

my $toname = 'bar_' . ('z' x 200);
ok copy ($longname, $toname) or diag $!;
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Maybe your O/S or your filesystem is the problem here?

I don't think file system issue because other files in that folder are copied. I suspect only the file name issue. Can we copy the whole directory along with sub dir and files in one line of code?

You may be interested in Win32::Backup::Robocopy

You can look at File::Copy::Recursive or consider using your OS (Windows?) command line tools:

my $cmd = qq{xcopy /s "$source" "$target"};
system( $cmd ) == 0
    or die "Couldn't launch [$cmd]: $!/$?";
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