Uncaught TypeError: Cannot read property 'toLowerCase'

[jonhue]

Uncaught TypeError: Cannot read property 'toLowerCase' of undefined
    at jQuery.fn.init.val (jquery.self-bd7ddd393353a8d2480a622e80342adf488fb6006d667e8b42e4c0073393abee.js:8201)
    at applicationUsersRegisterIndexValidateUsername (index.self-1ec7504e1c62604622326b3b5cb2feeaaf573eaf947a783c2b32784ce33aa2d2.js:27)
    at HTMLInputElement.callback (index.self-1ec7504e1c62604622326b3b5cb2feeaaf573eaf947a783c2b32784ce33aa2d2.js:10)
    at checkElement (jquery.typewatch.self-c0e2658d2eb4075588545012bae9e075cce3c801af9b0720461d040daa5e5184.js:50)
    at timerCallbackFx (jquery.typewatch.self-c0e2658d2eb4075588545012bae9e075cce3c801af9b0720461d040daa5e5184.js:88)

Issue seems to be in jquery.typewatch.js:50 or jquery.typewatch.js:88

[jonhue]

Here is my initialization:

applicationUsersRegisterIndexInitTypewatch() runs whenever the page loads.

function applicationUsersRegisterIndexInitTypewatch() {
    var applicationUsersRegisterIndexTypewatchOptions = {
        callback: function() {
            applicationUsersRegisterIndexValidateUsername();
        },
        wait: 750,
        highlight: true,
        allowSubmit: false,
        captureLength: 2
    };

    $('[data-validate]').typeWatch(applicationUsersRegisterIndexTypewatchOptions);
};



function applicationUsersRegisterIndexValidateUsername() {
    var $this = $(this);

    $.get( $this.data('validate'), {
        username: $this.val()
    }).success(function() {
        $this.addClass('valid').parent().removeClass('field_with_errors');
        $this.closest('form').find('[type="submit"]').removeClass('disabled');
    }).error(function() {
        $this.removeClass('valid').parent().addClass('field_with_errors');
        $this.closest('form').find('[type="submit"]').addClass('disabled');
    });
};

[jonhue]

the issue was unrelated to typewatch.