my $rHash = \%hash;
for my $k1 = (sort keys %$rHash) #outer key, this works
[download]

Is this real code? # this should NOT "work"

I suppose you want

for my $k1 (sort keys %$rHash)
[download]

Oh, and BTW why this

my $rHash = \%hash;

additional level of referencing? (Given that you do it only to dereference it later)