APP-FND-01496: Cannot access application ORACLE password
Cause: Application Object Library was unable access your ORACLE password.
There is a very easy solution to this. Oracle stores all application users in FND_USER and all application related database user in FND_ORACLE_USERID. To correct the problem in the cloned instance this is what I suggested:
export FND_USER and FND_ORACLE_USERID tables from production.
create a temporary schema in the clone instance.
import FND_USER and FND_ORACLE_USERID from the export file into this temporary schema.
Take a backup of your current FND_USER and FND_ORACLE_USERID by using CTAS
create table fnd_user_
create table fnd_oracle_userid_
insert into fnd_user (select * from temporary.fnd_user);
insert into fnd_oracle_userid (select * from temporary.fnd_oracle_userid);
Once you do the above, you are back to the stage before the newbie DBA did any change.
This works with all 11i versions. I have not yet tested this in R12.