Kaltura_Client_Exception thrown

Invalid KS "MzkxMTg2OGEzYTQ5ODAwMWE1NDczNDljM2VjYThiZWY2NjEzYzcwN3wxMDE7OzE0NjcwNjIxNjA7MjsxNDY2OTc1NzYwLjY4NjE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"