Error The selected SAP Oracle database instance has never been configured.

I am trying to create a new backup task SAP/R3 with Data Protector 6.20 and when I set data:
ORACLE_HOME
SAPDATA_HOME
username
Password
Service
Backup and restore executables directory

I get this error message:

[12:8709] The selected SAP Oracle database instance has never been configured.

Environment variables, user settings database (as sysdba and SYSOPER), and the directory of the executable are correct.

What can be happening?
How could I fix it?

Thanks for the help