Oracle Error : ORA-21779 duration not active

Recently we encounter the error ORA-21779 duration not active, in the alert log. This error keeps repeating.

ORA-21779: duration not active
Cause: User is trying to use a duration that has been terminated.
Action: User should avoid performing such operation.

In the trace file , you will notice the below.

Errors in file ora_smon_610346.trc:
ORA-21779: duration not active
Fri Sep 17 14:25:54 2010

There are few problem that cause this, in below url show other issues. In our case this error keep repeating after few seconds. To solve this we do this.

After flushing the share pool , the error is no longer appeared

alter system flush shared_pool;

References:-

http://oraclequirks.blogspot.com/2006/07/ora-21779-brain-teaser.html