Kaltura_Client_Exception thrown

Invalid KS "MmYwZjI2OWI1MmU3ZTU5OWM0ZWQ3M2RjNzQxNzU0M2JiZWRmNTBkOHwxMDE7OzE0NzAwMjMzODU7MjsxNDY5OTM2OTg1LjY0Njg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"