Kaltura_Client_Exception thrown

Invalid KS "MjlkOThjNzEwYmM2ODJkYjVkYmExODFiN2Q5YzY1MTRjNWJhY2U1YnwxMDE7OzE0ODExMTk4MDc7MjsxNDgxMDMzNDA3LjY0OTk7QW5vbnltb3VzO2VkaXQ6Kg==", Error "-1,INVALID_STR"