Undefined index: XXX in accept_exposed_input() (line 1273 of sites\all\modules\views\handlers\views_handler_filter.inc)

Question

I am getting the following notice on the views edit page:

• Notice: Undefined index: l12agno in accept_exposed_input() (line 1273 of C:\xampp\htdocs\drupal7\sites\all\modules\views\handlers\views_handler_filter.inc).

• Notice: Undefined property: views_display::$handler in execute() (line 1134 of C:\xampp\htdocs\drupal7\sites\all\modules\views\includes\view.inc).

I have added a filter on a taxonomy term for which I have written a custom filter handler (by using _views_data_alter):

$data['taxonomy_term_data']['l12agno'] = array(
    'title' => t('L1/2 Agnostic'),
    'help' => t('Lx Agnostic filter'),
    'real field' => 'tid',
    'filter' => array(
      'handler' => 'views_handler_filter_lx_agnostic',
    ),
  );

the custom handler looks like this: here "categoryta" is a 3 level hierarchy.

class views_handler_filter_lx_agnostic extends views_handler_filter {

  function value_form(&$form, &$form_state) {
    parent::value_form($form, $form_state);
    if (!empty($form_state['exposed'])) {
      $form['value'] = array(
        '#type' => 'container',
        '#prefix' => '<div id="views_category_wrapper" class="clear-block container-inline">',
        '#suffix' => '</div>',
        '#tree' => TRUE,
      );
      $vocab = taxonomy_vocabulary_get_names();
      $tree = taxonomy_get_tree($vocab['categoryta']->vid, 0, NULL, TRUE);
      $options = array();
      foreach ($tree as $item) {
        if(!$item->deleted) {
          $options[$item->parents[0]][$item->tid] = $item->name;
        }
      }
      $form['value']['t0'] = array(
        '#type' => 'select',
        '#options' => isset($options[0])? $options[0] : array(),
        '#empty_value' => 0,
        '#empty_option' => t('All'),
        '#default_value' => 0,
      );
      if (isset($options[0])) {
        foreach ($options[0] as $tid => $title) {
          $form['value']['t' . $tid] = array(
            '#type' => 'select',
            '#options' => $options[$tid],
            '#empty_value' => 0,
            '#empty_option' => t('All'),
            '#default_value' => 0,
            '#states' => array(
              'visible' => array(
                ':input[name="l12agno[t0]"]' => array(
                  'visible' => TRUE,
                  'value' => $tid,
                )
              )
            )
          );
        }
      }
    }
  }

  function query() {
    $this->ensure_my_table();
    if (!empty($this->value[0]['t0'])) {
      $t0 = 't' . $this->value[0]['t0'];
      if(!empty($this->value[0][$t0])) {
        $field = "$this->table_alias.$this->real_field";
        $this->query->add_where($this->options['group'], $field, $this->value[0][$t0], '=');
      }
      else {
        $def = $this->definition;
        $def['table'] = 'taxonomy_term_hierarchy';
        if (!empty($this->table_alias)) {
          $def['left_table'] = $this->table_alias;
        }
        else {
          $def['left_table'] = $this->table;
        }
        $def['left_field'] = $this->real_field;
        $def['field'] = 'tid';

        $join = new views_join();

        $join->definition = $def;
        $join->construct();
        $join->adjusted = TRUE;

        // use a short alias for this:
        $alias = $def['table'] . '_' . $this->table;

        $this->alias = $this->query->add_relationship($alias, $join, $alias . '_' . $this->real_field, $this->relationship);
        $this->query->add_where($this->options['group'], "$this->alias.parent", $this->value[0]['t0'], '=');
      }
    }
  }

  public function operators() {
    return array();
  }
}

The same code is working on production, but not in my local system. I have tried flushing cache and trying different browsers and switching between different jquery_update versions. Any help is appreciated.