Why isn't the value in the session available once the Location gets called?

Because you are over-writing it with an empty string here:

my $got_file_name = $cgi->param( 'doc_upload' ) || '';

# Store file name to use later.
$session->param("doc_uploaded", $got_file_name);

[download]

In reply to Re: Losing session value by hippo
in thread Lossing session value by Anonymous Monk

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