ORA-12638: Credential retrieval failed

Please assist to fix our issue. Thank you.

SQL> select dest_id,DEST_NAME,status,error from v$archive_dest where dest_id < 3;

  DEST_ID DEST_NAME           STATUS  ERROR

---------- ------------------------------ --------- ----------

     1 LOG_ARCHIVE_DEST_1       VALID

     2 LOG_ARCHIVE_DEST_2       ERROR   ORA-12638:

                          Credential

                          retrieval

                          failed

SQL> show parameter log_archive_dest_2

NAME                 TYPE    VALUE

------------------------------------ ----------- ------------------------------

log_archive_dest_2          string   SERVICE=maccdb_stb AFFIRM SYNC

                         VALID_FOR=(ONLINE_LOGFILES,PR

                         IMARY_ROLE) DB_UNIQUE_NAME=MAC

                         CDB_STB