EM 12c Cloud Control Re-Installation Fails at Repository Configuration With Error "RCU-6016:The spe

Applies to: Enterprise Manager Base Platform - Version: 12.1.0.1.0 and later   [Release: 12.1 and later ]
Information in this document applies to any platform.
Symptoms Installation of EM 12c Cloud Control fails at MDS Schema Configuration or it errors out in view log section as follows:
filename:/DATA/Middleware/oms/sysman/log/schemamanager/m_100911_0511_PM/m_100911_0511_PM.CREATE/emschema.log newly created:/DATA/Middleware/oms/sysman/log/schemamanager/m_100911_0511_PM/m_100911_0511_PM.CREATE/emschema.log jdbcUrl = jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=Evildead.idc.oracle.com)(PORT=1521)))(CONNECT_DATA=(SID=orcl))) Processing command line .... Repository Creation Utility - Checking Prerequisites Checking Global Prerequisites RCU-6016:The specified prefix already exists. RCU-6091:Component name/schema prefix validation failed. Processing command line .... Repository Creation Utility - Checking Prerequisites Checking Global Prerequisites RCU-6016:The specified prefix already exists. RCU-6091:Component name/schema prefix validation failed.
The OMS_HOME/sysman/log/schemamanager/m_/m_.CREATE/rcu.log has following error messages :
2011-10-09 17:24:50.450 TRACE rcu: oracle.sysman.assistants.rcu.backend.validation.StepValidator::setPrefixInfo: Detect query before variable substitution: 2011-10-09 17:24:50.450 TRACE rcu: oracle.sysman.assistants.rcu.backend.validation.StepValidator::setPrefixInfo: Detect query after variable substitution: 2011-10-09 17:24:50.453 TRACE rcu: oracle.sysman.assistants.rcu.backend.validation.StepValidator::isConnectionStepValidated: Leaving. 2011-10-09 17:24:50.453 ERROR rcu: oracle.sysman.assistants.rcu.backend.RCUCommandLineParser::setComponentSelections: RCU-6016:The specified prefix already exists. 2011-10-09 17:24:50.453 NOTIFICATION rcu: oracle.sysman.assistants.common.util.SilentMessageHandler::writeToLog: RCU-6016:The specified prefix already exists. 2011-10-09 17:24:50.453 ERROR rcu: oracle.sysman.assistants.rcu.backend.SilentRCUModel::performOperation: RCU-6091:Component name/schema prefix validation failed. 2011-10-09 17:24:50.453 NOTIFICATION rcu: oracle.sysman.assistants.common.util.SilentMessageHandler::writeToLog: RCU-6091:Component name/schema prefix validation failed.
Cause The repository was cleaned-up using
"drop user"command instead of
"RepManager dropall". Due to this, the resulting repository record for the sysman_mds, sysman_opss, sysman_apm schemas are not cleaned-up.
Solution 1. Connect to the repository database an ADMIN user and execute the following SQL statement: SQL> select comp_name from SCHEMA_VERSION_REGISTRY;

COMP_NAME
--------------------------------------------------------------------------------
Authorization Policy Manager
Metadata Services
Oracle Platform Security Service
2. If any row is returned, delete it with one or all the folling SQL statements: SQL> delete from SCHEMA_VERSION_REGISTRY where COMP_NAME='Authorization Policy Manager';
SQL> delete from SCHEMA_VERSION_REGISTRY where COMP_NAME='Oracle Platform Security Services';
SQL> delete from SCHEMA_VERSION_REGISTRY where COMP_NAME='Metadata Services';
SQL> commit;