message usually means one of the following conditions has occurred:
1) The ORACLE_HOME is not set correctly
- this often happens with scripts that are run using cron, at, the Oracle scheduler, or during system startup. We often set the ORACLE_HOME in the /etc/profile ... but that is not invoked by cron, etc. So we need to set the environment variables manually in our scripts.
2) The language setting is incorrect, or indicates a message language that is not loaded
3) The mesg directory or files have become corrupt