Kaltura_Client_Exception thrown

Invalid KS "MmIzOGJmZjNiMGQ1MzU1M2ZlMjEwNTlkMzZmZWJlMzA2MTA5Njk0N3wxMDE7OzE0NzUwODQwNDE7MjsxNDc0OTk3NjQxLjAwOTU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"