Kaltura_Client_Exception thrown

Invalid KS "NmU5MzllOGE5ODIyZjBmNzQ3ZDJiMjZkOGNmNDkwMzkzNmQ0MjE1NnwxMDE7OzE0OTMxOTAyNjE7MjsxNDkzMTAzODYxLjY0NDc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"