Kaltura_Client_Exception thrown

Invalid KS "NWZmNmEzMzlmYzUwYTI0MWVlZmUwZTI1ZWMyNjgwMDU1NDA1OTc5MnwxMDE7OzE0NzQ5MDYzMTM7MjsxNDc0ODE5OTEzLjkyODY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"