Client fails with “Failed to notify session of closed connection: FAIL_TERMINATED” on dispose while Resume is configured #1115

I created a simple client and server spring boot application with rsocket and simple resume enabled.
Every time the client tries to dispose, I get the error message: “Failed to notify session of closed connection: FAIL_TERMINATED”

Expected Behavior

I expect the RSocket connection to close gracefully (especially when using resume) without throwing the exception “Failed to notify session of closed connection: FAIL_TERMINATED.”

Actual Behavior

When shutting down the client or server, the following error appears in the logs:

2025-01-22T11:59:06.211+01:00 ERROR 7399 --- [client] [actor-tcp-nio-2] i.r.resume.ResumableDuplexConnection : Side[client]|Session[iY��-�M����rY�]|DuplexConnection[1]. Failed to notify session of closed connection: FAIL_TERMINATED

The connection does close, but this error suggests a potential issue with the session being abruptly terminated rather than cleanly closed.

Steps to Reproduce

I created a public github repository with sample code to show the error:
https://github.com/ansgarschulte/rsocket_client_server_resume_echo

First start the RSocketServerApplication and then the RSocketClientApplication.

You will see the error in the Client log.

Your Environment

• RSocket version(s) used: 1.1.3
• Other relevant libraries versions: spring.boot 3.4.1
• Platform:
  openjdk version "23.0.1" 2024-10-15
  OpenJDK Runtime Environment Zulu23.30+13-CA (build 23.0.1+11)
  OpenJDK 64-Bit Server VM Zulu23.30+13-CA (build 23.0.1+11, mixed mode, sharing)
• OS and version: MacOS 15.2