VivoxCore for Unreal Engine 4

Question

Has anyone used VivoxCore for unreal engine 4 and know what this error means? I'm not able to really understand what this means. I've tried reading through the source code for vivox, as well as the documentation and that error code (1105) is mentioned nowhere. Also, the company which makes this does not respond to emails, and their public forum is not active. I've tried calling them, emailing them, using the public forum, reading online for answers, and I've found nothing, so stackoverflow is my last option. I hope someone here can help me.

LogVivoxVoiceChat: Warning: onConnectFailed server:https://vdx5.www.vivox.com/api2 error:SIP Backend Required (1105)

Here is my code:

VoiceChat = (FVivoxVoiceChat*)FVivoxVoiceChat::Get();

    if (!VoiceChat->IsInitialized())
    {
        GLog->Log("Is not initialized, trying to initialize.");
        VoiceChat->Initialize();
        return;
    }

    if (!VoiceChat->IsConnected())
    {
        GLog->Log("Is not connected, trying to connect.");
        VoiceChat->Connect(FOnVoiceChatConnectCompleteDelegate::CreateLambda([](const FVoiceChatResult& Result)
            {

            }));
        return;
    }

    FString PlayerName = PlayerState->GetPlayerName();
    FString LoginToken = VoiceChat->InsecureGetLoginToken(PlayerName);

    if (!VoiceChat->IsLoggedIn())
    {
        GLog->Log("Is not logged in, trying to login.");
        VoiceChat->Login(0, PlayerName, LoginToken, FOnVoiceChatLoginCompleteDelegate::CreateLambda([](const FString& LoggedInPlayerName, const FVoiceChatResult& Result)
            {

            }));
        return;
    }

    FString ChannelName = "TestChannel";
    EVoiceChatChannelType ChannelType = EVoiceChatChannelType::Echo; // Echo for testing. 
    TOptional<FVoiceChatChannel3dProperties> Channel3dProperties;
    FString JoinToken = VoiceChat->InsecureGetJoinToken(ChannelName, ChannelType, Channel3dProperties);

    VoiceChat->JoinChannel(ChannelName, JoinToken, ChannelType, FOnVoiceChatChannelJoinCompleteDelegate::CreateLambda([](const FString& JoinedChannelName, const FVoiceChatResult& Result)
        {
            GLog->Log("JOin Channel successful");
        }), Channel3dProperties);

    VoiceChat->TransmitToSpecificChannel(ChannelName);

Answer 1

Try disabling the Vivox Interface plugin if it's enabled.

Answer 2

This error means that you have an outdated SDK. The SDK included in UE4 is outdated: it is using backend version 4, but the actual version is 5.