Kaltura_Client_Exception thrown

Invalid KS "Yzc3MGE2MmFiNzVmZjRlODI1OTcyNDA2NTJkYmI1NGY4N2U1NTk5YXwxMDE7OzE0NzUyNjI3NTA7MjsxNDc1MTc2MzUwLjY0NTM7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"