When opening a K2 article in the Admin area, I get this error message:

Notice: Undefined property: JSimpleXMLElement::$params in /home/MYSITENAME/public_html/libraries/joomla/html/parameter.php on line 398

When I try to create a new item or save one it goes to a blank page. It will not save images but sometimes manages to save the article text changes. I have to use the back button to go back to the article.

If I disable CSS4K2 the error goes away.

Any help would be appreciated.