ORA-01017 on login to database as SYS as SYSDBA remotely

Here's what I see:
[oracle_at_mappr2 ~]$ . oraenv

ORACLE_SID = [MY_DB] ?
The Oracle base remains unchanged with value /u01/app/oracle
[oracle_at_mappr2 ~]$ orapwd file=?/dbs/orapw_at_ force=y password=MyPassword123
ignorecase=no
[oracle_at_mappr2 ~]$ ls -l $ORACLE_HOME/dbs/orapwMY_DB
-rw-r----- 1 oracle oinstall 7680 Jul 3 19:24 /u01/app/oracle/product/12.1.0/dbhome_1/dbs/orapwMY_DB
[oracle_at_mappr2 ~]$ . oraenv

ORACLE_SID = [MY_DB] ?
The Oracle base remains unchanged with value /u01/app/oracle
[oracle_at_mappr2 ~]$ sqlplus sys/MyPassword123_at_MY_DB as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Mon Jul 3 19:25:31 2017

Copyright (c) 1982, 2014, Oracle. All rights reserved.

ERROR:
ORA-01017: invalid username/password; logon denied ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory Additional information: 3

Enter user-name: / as sysdba

Connected to:
Oracle Database 12c Standard Edition Release 12.1.0.2.0 - 64bit Production With the Automatic Storage Management option

SQL> select * from v$pwfile_users;

no rows selected

SQL> show parameter remote_login_passwordfile

NAME TYPE VALUE

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

Also, since I'm seeing the unable to obtain file status' error, I tried tracing sqlplus with 'strace -ftt', but when I grepped the output for 'open' call and then for 'orapw' I don't even see any attempt to open the password file?

Anyhow, I've got an SR open w/ Oracle, but if anyone has any suggestions, I'm all ears.

Thanks,

-Mark

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