Javascript error on submission : using client side ajax validation

If i switch on Client Side Ajax Validation – the validation appears to work correctly and the fields will show and error or go-green with user input. But when i click SEND – it does nothing and the console (chrome) prints :

Uncaught TypeError: Cannot read property ‘length’ of undefined

Note : I apache password protected the wp-admin directory in the vhost, but have allowed wp-admin/admin-ajax.php to be accessible without auth.

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