Kaltura_Client_Exception thrown

Invalid KS "YWNiYWQzNWJhOGRjOTk3ZWUzNzI4ODRlZGExN2YwMTcyZTQwMDRmNHwxMDE7OzE0OTgzOTQ4NzY7MjsxNDk4MzA4NDc2Ljc2OTY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"