Common problem. "(" denotes a list, "[" creates an anonymous array out of a list, and "{" creates an anonymous hash out of a list. You initialize a hash (%fields) by giving it a list. Doing:

my %fields= { a=>1, b=>2 };
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tries to init %fields with a list of one item, that is, tries to set the key to be a hash ref, {a=>1,b=>2}, and provides no value for that key. Just like you don't write:

my @list= [ 0, 1, 2 ];
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unless you want an array that contains just one item (and that item is a reference to an anonymous array that contains 3 items).

Does that help?

        - tye (but my friends call me "Tye")