Kaltura_Client_Exception thrown

Invalid KS "MWEwOTZiZGVmNjU1ODFjNzE0M2FkMzI3NzRmYzZjMDgwOTI0M2MyYXwxMDE7OzE0NzUwMjkzMzQ7MjsxNDc0OTQyOTM0LjEwNjg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"