Kaltura_Client_Exception thrown

Invalid KS "Nzc3Yjc1YjA2MWQ1MmYzNmMwYjgxZjEwYmRmNGQxNjRhMjhiNTU4MHwxMDE7OzE0NzUzNTQxMTU7MjsxNDc1MjY3NzE1LjMzMzE7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"