title: Custom post type with category results in error
body: <p>I don't know what I'm doing wrong. I have a custom post type called <code>models</code>. Within this custom post type I register also a custom taxonomy. This custom taxonomy is used for categories. But I getting every time a 404 error.</p>
  
  <p><strong>This is how I create my custom post type:</strong></p>
  
  <pre><code>$labels = array(
          'name' =&gt; __('Modellen', 'models'),
          'singular_name' =&gt; __('Model', 'models'),
          'add_new' =&gt; __('Nieuwe toevoegen', 'models'),
          'add_new_item' =&gt; __('Nieuw model', 'models'),
          'edit_item' =&gt; __('Model bewerken', 'models'),
          'new_item' =&gt; __('Nieuw model', 'models'),
          'view_item' =&gt; __('Model bekijken', 'models'),
          'search_items' =&gt; __('Model zoeken', 'models'),
          'not_found' =&gt; __('Niks gevonden', 'models'),
          'not_found_in_trash' =&gt; __('Niks gevonden in de prullenbak', 'models'),
          'parent_item_colon' =&gt; __('Model', 'models'),
          'menu_name' =&gt; __('Modellen', 'models'),
      );
  
      $args = array(
          'labels' =&gt; $labels,
          'hierarchical' =&gt; false,
          'supports' =&gt; array('title', 'page-attributes', 'editor', 'excerpt', 'author', 'thumbnail', 'custom-fields', 'revisions'),
          //'taxonomies'  =&gt; array('category'), // Old
          //'taxonomies'  =&gt; array('category'), // New not used any more
          'public' =&gt; true,
          'show_ui' =&gt; true,
          'show_in_menu' =&gt; true,
          'menu_position' =&gt; 20,
          'show_in_nav_menus' =&gt; true,
          'publicly_queryable' =&gt; true,
          'exclude_from_search' =&gt; false,
          'has_archive' =&gt; true,
          'query_var' =&gt; true,
          'can_export' =&gt; true,
          'rewrite' =&gt; false,
          'capability_type' =&gt; 'post',
      );
  
      register_post_type('models', $args);
      //register_taxonomy_for_object_type('category', 'models'); // Old
      //register_taxonomy_for_object_type('category', 'models'); // New not used any more
  </code></pre>
  
  <p><strong>This is how I create my custom taxonomy:</strong></p>
  
  <pre><code>$labels = array(
          'name'              =&gt; _x('Categorieën', 'taxonomy general name', 'textdomain'),
          'singular_name'     =&gt; _x('Categorie', 'taxonomy singular name', 'textdomain'),
          'search_items'      =&gt; __('Zoek Categorieën', 'textdomain'),
          'all_items'         =&gt; __('All Categorieën', 'textdomain'),
          'parent_item'       =&gt; __('Hoofd categorie', 'textdomain'),
          'parent_item_colon' =&gt; __('Hoofd categorie:', 'textdomain'),
          'edit_item'         =&gt; __('Bewerk categorie', 'textdomain'),
          'update_item'       =&gt; __('Update Categorie', 'textdomain'),
          'add_new_item'      =&gt; __('Nieuwe categorie', 'textdomain'),
          'new_item_name'     =&gt; __('Nieuwe categorie naam', 'textdomain' ),
          'menu_name'         =&gt; __('Categorieën', 'textdomain'),
      );
      $args = array(
          'labels' =&gt; $labels,
          'hierarchical' =&gt; true,
          'public' =&gt; true,
          'publicly_queryable' =&gt; true,
          'show_ui' =&gt; true,
          'show_in_menu' =&gt; true,
          'show_in_nav_menus' =&gt; true,
          'show_in_rest' =&gt; false,
          'show_tagcloud' =&gt; false,
          'show_in_quick_edit' =&gt; true,
          'show_admin_column' =&gt; false,
          'rewrite' =&gt; array('slug' =&gt; 'models', 'hierarchical' =&gt; true),
      );
      //register_taxonomy('category', array('models'), $args); // Old
      register_taxonomy('cat_models', array('models'), $args); // New
  </code></pre>
  
  <p>Thanks!</p>
  
  <p><strong>Edit:</strong><br>
  Maybe good to mention: </p>
  
  <ul>
  <li>I execute the code inside my own custom plugin.</li>
  <li>I use the default Twenyseventeen theme</li>
  <li>WordPress 4.8</li>
  </ul>
  
  <p><strong>Solution:</strong>
  Thanks to @AmitJoshi I needed to change the category to something else.
  Above the updated code with the changes.</p>