Kaltura_Client_Exception thrown

Invalid KS "MzM2YjliOWUxNzdhN2MyYWQyNGIxNTQ0NWI5NzY5MmRjYjM0YjljZXwxMDE7OzE0OTU5MTI3NzA7MjsxNDk1ODI2MzcwLjAwMjc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"