Kaltura_Client_Exception thrown

Invalid KS "N2ZjZDY2ZWVjMWE4NTk1NWVkNGZhZTQxYzQxZWFiOGI3OGRjMmRjNHwxMDE7OzE0OTU2NTk2MjU7MjsxNDk1NTczMjI1LjM0NTc7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"