The Enforce web interface is inaccessible with an error "HTTP Status 404 -" and the DLP tomcat log is full of various database connection errors. Upon testing the connection to the Oracle database from the Enforce server with the SQLPlus utility, you receive the error:
ORA-00257: archiver error. Connect internal only, until freed.
This error indicates the Oracle database is in a degraded or failed state and is no longer accepting new connections. Please have the Oracle DBA investigate the health of the database and resolve any issues found, particularly in the alert log. Once the database issues are resolved, restart the DLP Enforce services to ensure there is a good connection to the database.