Encountering difficulties in registering the BDRShield Backup Server with the 360 Server may result from various reasons:

1. 360 Server is not installed, or the 'BDRShield 360 Server' service is not running on the target machine.

2. The Registration Key is not provided, or the entered Registration Key is incorrect.

3. Invalid Port Number.

4. Issues with Internet Connection.

5. The specified IP Address/DNS name is not a 360 Server.

6. BDRShield Backup Server and 360 Server versions are not compatible.

Cause 1:

Make sure the BDRShield 360 Server is installed on the target machine whose IP Address/DNS name is provided. Verify the service status:

1. Press 'Win + R' to open the 'Run' window.
2. Type 'services.msc' and click OK.
3. Ensure the 'BDRShield 360 Server' service is running.
   

Cause 2:

1. If 'BDR Server Authorization' is enabled on the 360 Server, a Registration Key is required for authorization.
2. Contact the BDRShield Administrator to obtain the correct Registration Key.
3. Provide the valid Registration Key on the BDRShield Server for connection.
   

Cause 3:

Ensure the correct web server port for the 360 Server:

1. Default HTTP port: 6060
2. Default HTTPS port: 6061
3. If customized during installation, edit and provide the current port number in use.
   

Cause 4:

1. Confirm that the BDRShield server has internet connectivity.
2. Check for issues with the proxy server or credentials provided on the server.
   

Cause 5:

1. Ensure that no other product or BDRShield product is running on the specified machine.
2. Provide the IP Address/DNS name where the 360 Server is installed and running.
   

Cause 6:

Register the 360 Server with the BDRShield Server only if both servers are running the same version.