During installation, when running "oracle_create_user.sql" from SQLPlus, the following messages show up:
Connected.
Profile altered.
DROP USER protect
*
ERROR at line 1:
ORA-01918: user 'PROTECT' does not exist
User created. User altered.
User altered.
Grant succeeded.
Grant succeeded.
...
If this is an installation, then this is an expected error and can be ignored.
During the creation of the "protect" oracle account, or whatever username is designated for the oracle account, the script will first attempt to "drop" or eliminate any other user accounts that have the same name. This assures that the account is created without overwriting an existing account. Since a fresh system should not have an existing account, the ORA-01918 error is completely expected and ignorable.
Needless to say, running this script on an existing installation is dangerous as "dropping" the schema owner will eliminate all DLP information in the database. Database restoration from backup would then be needed.