IsObjectMonoBehaviour can only be called from the main thread.

Hello! After a long discussion with our game engine developer, it turned out as the specific code (which I added the RestClient to) was deliberately called from a separated thread, OTHER than unity main thread. Our problem has disappeared by adjusting the location of the communication functions (which is IN the unity main thread) I dont know RestClient was meant to work even if it was called from a separated thread or not. but at this point it would be efficient to close this issue and reopen when it is needed!

Thank you for all your support and again for this great work!

Sorry I cant share all of the relevant codes (we are working for some other people so it’s not entirely up to us)

part of the code which calls RestClient functions:

   public void SendAllLogs(string bigJson)
    {
        string sendAllLogsUrl = restBaseUrl + "/logs";> 

        byte[] bigJsonUTF8CompB = CompressionHelper.CompressBytes(
                System.Text.Encoding.Convert(
                    System.Text.Encoding.Default, System.Text.Encoding.UTF8,
                    System.Text.Encoding.Default.GetBytes(bigJson)
                    )

            );

        RequestHelper rh = new RequestHelper
        {
            Uri = sendAllLogsUrl,
            Method = "POST",
            Headers = this.headers,
            ContentType = "application/octet-stream",
            BodyRaw = bigJsonUTF8CompB,
        };
        
        RestClient.Post(rh).Then(res =>
        {
            JsonData data = JsonMapper.ToObject(res.Text);

            // some codes to run when successful                 

        }
        ).Catch(err =>
        {
            // Log Error
        }
        );
    }

above code is called (through some instances and methods) from a monobehavior script attached on the gameobject which controls the entire game. sorry i cant share more about this …

Altough I have confirmed that:

1. When above error happens, it is actually on a non-main thread by using and comparing System.Thread.CurrentThread

2. The game uses UniRx package & it’s multithreading functions :https://github.com/neuecc/UniRx

3. I confirmed that inside of DontDestroyOnLoad, gameobject “Static Coroutine RestClient” is created and continues working when the same function is called on the main thread. (and continues giving us the same error when called on a non-main thread) (there also is DontDestroyOnLoad/MainThreadDispatcher which is created by UniRX package)

If you need any more info about this please let me know! Thank you!!