Kaltura_Client_Exception thrown

Invalid KS "MzUyNjM5MThiZmU3YWEyYzkxM2VlYmM1OGUwZDE4MmZjZTA2M2NiN3wxMDE7OzE0NzQ5MTkxMzA7MjsxNDc0ODMyNzMwLjk2Mjg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"