Kaltura_Client_Exception thrown

Invalid KS "ZmFhMzFmYTQwYmI1NWIyMjYwNTQzYzQzMWUxODUwNDUzZDRhYzRiZHwxMDE7OzE0NzQ4NTc0NDI7MjsxNDc0NzcxMDQyLjE0NjE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"