Kaltura_Client_Exception thrown

Invalid KS "MTlhMzE4ZWIxYzllNTdmMGZkNDZhMmM5NzhjOWVkZTIwN2ZjYjg5Y3wxMDE7OzE0OTM1MzY3NDI7MjsxNDkzNDUwMzQyLjkzNDI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"