title: Getting warning while deleting custom fields
body: <p>I have created a custom post type and added custom fields in the WordPress backend as you can see in the screenshot <img src="https://i.stack.imgur.com/EoIkE.png" alt="enter image description here"></p>
  
  <p>But now when I try to delete this custom field, getting this warning</p>
  
  <p><code>You do not have permission to do that.</code></p>
  
  <p>I am bit confused as why this warning is showing up as I am already logged in with Administrator account.</p>
  
  <p>I have developed a plugin for creating custom post type below is the code</p>
  
  <pre><code>public function charities_register_plugin() {
  
      $labels = array(
          'name' =&gt; _x('Charities', 'charities'),
          'singular_name' =&gt; _x('Charity', 'charities'),
          'add_new' =&gt; _x('Add New', 'charities'),
          'add_new_item' =&gt; _x('Add New Charity', 'charities'),
          'edit_item' =&gt; _x('Edit Charity', 'charities'),
          'new_item' =&gt; _x('New Charity', 'charities'),
          'view_item' =&gt; _x('View Charity', 'charities'),
          'search_items' =&gt; _x('Search Charity', 'charities'),
          'not_found' =&gt; _x('No charities found', 'charities'),
          'not_found_in_trash' =&gt; _x('No charities found in Trash', 'charities'),
          'parent_item_colon' =&gt; _x('Parent Charity:', 'charities'),
          'menu_name' =&gt; _x('Charities', 'charities'),
      );
  
      $args = array(
          'labels' =&gt; $labels,
  
          'hierarchical' =&gt; true,
          'description' =&gt; 'Allow Admin to create charities',
          'supports' =&gt; array('title', 'editor', 'revisions','custom-fields'),
          'public' =&gt; true,
          'show_ui' =&gt; true,
          'show_in_menu' =&gt; true,
          'show_in_nav_menus' =&gt; true,
          'exclude_from_search' =&gt; true,
          'has_archive' =&gt; true,
          'publicly_queryable' =&gt; true,
          'query_var' =&gt; true,
          'can_export' =&gt; true,
          'rewrite' =&gt; array("slug" =&gt; "mycharities",'with_front'=&gt;FALSE)
      );
  
      register_post_type('charities', $args);
  
  }
  </code></pre>
  
  <p>And trigger it using </p>
  
  <p><code>add_action('init', array($this, 'charities_register_plugin'));</code></p>
  
  <p>Any help will be very much appreciated.</p>