Kaltura_Client_Exception thrown

Invalid KS "MDI4NjMxYWFiZDEzZDljMWY0ODI2NWE2NzU4OGI4ODRlMWIyZjJkN3wxMDE7OzE0NzUwNTk1MjU7MjsxNDc0OTczMTI1LjY0NDg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"