Kaltura_Client_Exception thrown

Invalid KS "NDk2MmQ5NzQ1NmNjMGM1YTY5MmIzMjBkYWZmMDU0ZWQ3NjJjYzA0NHwxMDE7OzE0NzUyMDc3NDI7MjsxNDc1MTIxMzQyLjM5NDE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"