I have implemented SignalR in my Android application, but I have encountered some issues that are causing exceptions to be thrown.
An unexpected error occurred invoking ‘Subscribe’ on the server. TimeoutException: Ack-able message Microsoft.Azure.SignalR.Protocol.JoinGroupWithAckMessage(ackId: 7644) timed out. Fatal Exception: io.reactivex.rxjava3.exceptions.OnErrorNotImplementedException
The exception was not handled due to missing onError handler in the subscribe() method call.com.microsoft.signalr.HubException: An unexpected error occurred invoking ‘Subscribe’ on the server. TimeoutException: Ack-able message Microsoft.Azure.SignalR.Protocol.JoinGroupWithAckMessage(ackId: 47043) timed out.

I have implemented it.

hubConnection?.start()?.blockingAwait()
if (hubConnection?.connectionState == HubConnectionState.CONNECTED) {

            val con = hubConnection.invoke(
                "Subscribe",
                hubConnection.connectionId,
                arrayListOf(
                    currentUserId,
                    currentUserId + "method_name",
                    currentUserId + "method_name",
                    currentUserId + "method_name",
                    currentUserId + "method_name",
                    currentUserId + "method_name",
                    currentUserId + "method_name"
                )
            )

            con.doOnError { error ->
                if (error != null) {
                    hubConnection.stop()
                }
            }

            con.subscribe()

        

        } 

when any error occurs the con.doOnError does not catch that error