Kaltura_Client_Exception thrown

Invalid KS "MjRjMjUzNTFkZDAwZGUwNzM0N2ViOGJhODFhNmMxOTNiMTI3MWM4NHwxMDE7OzE1MDExNTM0NTc7MjsxNTAxMDY3MDU3LjI0MDk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"