Kaltura_Client_Exception thrown

Invalid KS "YzUwNjg1ZTViN2VjZGQxZTAzZDZjZTVjODg4NzgyMDBkYTRkNjJhY3wxMDE7OzE0NzUxNTE4NTI7MjsxNDc1MDY1NDUyLjM5ODU7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"