Caused by: java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is:

This error message indicates that the Java Remote Method Invocation (RMI) client was not able to establish a connection with the RMI server running on the local host (127.0.0.1). This could be due to a variety of reasons such as firewall settings, incorrect server configuration, or network connectivity issues. In order to resolve this issue, you can try the following:

1. Check if the RMI server is running on the local host and listening on the correct port.
2. Verify that there are no firewall rules blocking the RMI traffic.
3. Make sure that the RMI client and server are using the same RMI registry.
4. Check your network settings to ensure that there are no connectivity issues between the RMI client and server.
5. If the RMI server is running on a remote host, make sure that the hostname or IP address is correct and reachable from the client machine.

If none of these solutions work, you may need to consult your system administrator or network engineer for further assistance.