I believe you might be victim to a misindentified line, or yourself misindentifying it. This code looks wrong to me: 
elsif (($blast_par->{$cleancodes->[$y]}->{"defline"}->[$y] !~ m/NP_/) 
+&&
($blast_par->{$cleancodes->[$x]}->{"defline"}->[$x] =~ m/NP_/)) {

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$blast_par->{$cleancodes->[$x]}->{"defline"} should point to "description", but you then add ->[$x] which attempts to dereference "description" as an array.

In reply to Re: strict refs and REGEXP error by Sifmole
in thread strict refs and REGEXP error by professa

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