Kaltura_Client_Exception thrown

Invalid KS "MDMzZDU3NGQ3ZDBmMzlhMGU1MDRiMDRjMmMwMjhlNWRhNmQwZTIzOHwxMDE7OzE0NzUyNjMzMjY7MjsxNDc1MTc2OTI2LjkyNDY7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"