Then I’d think something is wrong with the user you’re logging in with. Perhaps some code - with a bug causing the error you see - is executed upon login?
I’d inform your DBA from the problem you have.
Hey Pras – The next thing I would try is try to login using sqlplus as the same user from a different machine where a different user has been successful logging in. If that works, it is most likely something in your client configuration on your machine. If it throws the same error, then it is most likely something with that user or some logon trigger or other code that is fired off is blowing up for that user and it would have to go back to the DBA.
There is a free tool come with SQL Navigator called “Quest SQL Tracker” You can use this tool to monitor SQL Navigator during login and it may give you an idea what’s going on.
Start Menu -> All Programs -> Quest Software -> SQL Navigator x -> Quest SQL Tracker