Kaltura_Client_Exception thrown

Invalid KS "MjFlOWEzYmZiOTJhZTkwOGFiMDVjODRlZDMxZTAwOGU3OTlhZWJlNXwxMDE7OzE0NzQ4NjMzMTA7MjsxNDc0Nzc2OTEwLjkxODQ7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"