Workaround 1: Change the geodatabase administrator (SDE) password through SQL*PLUS:
Alter user SDE identified by <PASSWORD>;
Workaround 2: To prevent this from reoccurring, set the profile to have an UNLIMITED PASSWORD_LIFE_TIME and UNLIMITED PASSWORD_GRACE_TIME in SQL*PLUS while connected as sys or system:
SELECT PROFILE
FROM dba_users
WHERE username = 'SDE';
Use the profile returned from executing the above query in place of the <PROFILE> in the following queries:
ALTER PROFILE <PROFILE> limit password_life_time UNLIMITED;
ALTER PROFILE <PROFILE> limit password_grace_time UNLIMITED;
ALTER USER <USER name> IDENTIFIED BY <password>;