Connection version error for empty handshake.

Unity Engine
1

Hi all, I run ROS on windows and connect with TCP endpoint v7.0.0, ROS 1.15.9, and Unity 2021.3.12
Everything was going fine, but suddenly I began to have this error.
The same setup works perfectly on another PC. I’ve found that the content of the handshake on line 879 of ROSConnection is empty and the script interprets there is a version error.

        static async Task ReaderThread(int readerIdx, NetworkStream networkStream, ConcurrentQueue<Tuple<string, byte[]>> queue, int sleepMilliseconds, CancellationToken token)
        {
            // First message should be the handshake
            Tuple<string, byte[]> handshakeContent = await ReadMessageContents(networkStream, sleepMilliseconds, token);

            if (handshakeContent.Item1 == SysCommand.k_SysCommand_Handshake)
            {
                ROSConnection.m_HasConnectionError = false;
                queue.Enqueue(handshakeContent);
            }
            else
            {
                Debug.LogError($"Invalid ROS-TCP-Endpoint version detected: 0.6.0 or older. Expected: {k_Version}.");
            }

Actually, if I comment these lines as if the handshake was correct, I can send and receive the messages. Is it a known issue? I haven’t found info about it.

8888622--1215444--upload_2023-3-20_11-39-4.png
8888622--1215444--upload_2023-3-20_11-39-4.png775×542 152 KB

2

Yes your Unity-ROS-bridge has not the same version as the ROS-TCP endpoint you are using in the editor. Did you made an update on any side?

3

As I mentioned, the empty handshake content is triggering this error, but the version is the right one on both sides. The same code works perfectly on another machine.
Btw, despite this error, I receive messages from the TCP endpoint in Unity, but I cannot send them.