Kaltura_Client_Exception thrown

Invalid KS "NDM0ZWRkY2YzYjkxZDhmMjFkYjU3NjJkYmM2M2FlZDUyYzgyOGE5NXwxMDE7OzE0ODUzMTQ4MDM7MjsxNDg1MjI4NDAzLjQ1NTg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"