Four things:

1. Are you sure the ENV variables are set properly on the new machine? What do you get when you run the following in terminal for both machines?

echo REQUEST_METHOD: $REQUEST_METHOD
echo CONTENT_LENGTH: $CONTENT_LENGTH
echo QUERY_STRING:   $QUERY_STRING
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2, On which line is the uninitialized value reported?

3. Put the following at the top of your script below the shebang:

use strict;
use warnings;
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4. Now what warnings/errors do you see? (Be sure to declare your variables w/ my)