Symptoms
While trying to upgrade or install the product on Linux/Unix we ask for the Oracle password then throw the invalid username/password error.
Cause
If you have a remote DB and your on a Linux/Unix system you need to set TWO_TASK.
Resolution
From the command line run:
TWO_TASK=<Oracle SID>; export TWO_TASK
Just replace <Oracle SID> with the SID to this database. Your DBA should know this or how to find.
Once this is done run the install again. You can make sure it is set by using before running the install:
echo $TWO_TASK
It should return the SID.