Fix ORA Error in Navicat Oracle Connection

If Navicat encounters an ORA error when connecting to Oracle, it may be due to the following reasons:

1. The Oracle database service is not started: Please ensure that the Oracle database service is started correctly.
2. Database connection parameters error: Please check if the connection parameters are correct, including the hostname, port number, username, and password.
3. Firewall or network issue: Please check the firewall settings to ensure that Navicat is allowed to access the port number for the Oracle database.
4. Oracle database configuration issue: Please verify if the Oracle database configuration files, such as listener.ora and tnsnames.ora, are correct.
5. The Oracle database version is not compatible: Please ensure that the Navicat version you are using is compatible with the Oracle database version.

Solution:

1. Check if the Oracle database service has been successfully started. You can check the status of the Oracle service in Windows services.
2. Check if the Navicat connection parameters are correct. You can try using other Oracle client tools for connection testing, such as SQL Developer.
3. Check the firewall settings to ensure that the port number for accessing the Oracle database with Navicat is allowed. You can try disabling the firewall or adding the appropriate port exception.
4. Check the configuration file of the Oracle database. You can try using tools like SQL*Plus to connect to the Oracle database and verify if the configuration file is correct.
5. Make sure that Navicat is compatible with the version of Oracle database being used. You can refer to the compatibility list for Navicat and Oracle database to ensure that the appropriate version is being used.

If the above methods fail to resolve the issue, we suggest reaching out to the Oracle database administrator or contacting Navicat official support for further assistance.