| The user attempted to issue a privileged administrative command, but could not be successfully authenticated by the listener using the local OS authentication mechanism. This may occur due to one of the following reasons:
1. The user is running a version of LSNRCTL that is lower than the version of the listener.
2. The user is attempting to administer the listener from a remote node.
3. The listener could not obtain the system resources needed to perform the authentication.
4. The local network connection between the listener and LSNRCTL was terminated unexpectedly during authentication message exchange, such as if LSNRCTL program was suddenly aborted.
5. The communication between the listener and LSNRCTL is being intercepted by a malicious user.
6. The software that the user is running is not following the authentication protocol, indicating a malicious user.