Kaltura_Client_Exception thrown

Invalid KS "MWM5ZjEwYjg4MmM1ZGY3NWI2OWY5NWUxZjMzZjY0M2MwMzczZGRmYXwxMDE7OzE0OTMxOTAzMjc7MjsxNDkzMTAzOTI3LjA4Nzg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"