Kaltura_Client_Exception thrown

Invalid KS "YWIxMGQ2N2ViODZkMDllNGQ2YjNlZTg0NzUwOWEyYzgyMzRkMWM3Y3wxMDE7OzE1MDExOTY0NDU7MjsxNTAxMTEwMDQ1Ljk2ODg7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"