This is an indication that there is a problem with the library NetVault Backup uses to integrate with RMAN. You may be able to browse the database in the GUI, but once NetVault Backup tries to use the library for a backup it will fail.
When the Oracle APM is installed it will link a library to the $ORACLE_HOME/lib directory in Linux or place the ORASBT.dll file in the system32 folder in Windows. In Linux you can see the link by using the ls -la command on the lib directory. You will need to remove the Oracle APM, manually remove this link or file and then reinstall the Oracle APM. If it won't let you remove the file, you may need to reboot the server first.
