Kaltura_Client_Exception thrown

Invalid KS "YzJiY2M3NDNlZjhhZTUwOGIzNzA5MTlkNzk2NWQ1MDYxYWViODYwN3wxMDE7OzE0OTgzNTc2MzU7MjsxNDk4MjcxMjM1Ljk4NTc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"