Kaltura_Client_Exception thrown

Invalid KS "Mzg5YmZlNzM2YWQ2NTU1ZDQzMzQyZmY4YThjZWM3NDA1NDRiYTU0ZHwxMDE7OzE1MDA4NTA5Mjc7MjsxNTAwNzY0NTI3Ljg0NjI7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"