Steps to reproduce the issue

Create new newsfeed with the url:

http://www.volleybal.nl/application/handlers/export.php?format=rss&type=vereniging&programma=8151&iRegionId=7000

On the 'Display' tab, set the 'Feed Display Order to' 'Oldest first'
Load the feed using an menu-item or some others means.

Expected result

No errors!

Actual result

The following errors are displayed (along the the content)

Notice: Undefined property: stdClass::$items in D:\Xampp\htdocs\hwvvbenevia\components\com_newsfeeds\views\newsfeed\view.html.php on line 191

Warning: array_reverse() expects parameter 1 to be array, null given in D:\Xampp\htdocs\hwvvbenevia\components\com_newsfeeds\views\newsfeed\view.html.php on line 191

System information (as much as possible)

Using Joomla 3.4.3

• XAMPP 3.2.1
• Apache/2.4.16 (Win32) OpenSSL/1.0.1p
• PHP/5.6.11
• MySQL 5.6.25

Additional comments

To remove the error, modify line 69 $items = $categoryModel->getItems(); in the following $item->items = $categoryModel->getItems();

The error will no longer be shown, however it seems the sorting functionality does not work art all :(.
Maybe a result of the complete rewrite of the newsfeed code starting with Joomla 3.0