InvalidOperationException at DSharpPlus.DiscordClient.UpdateUser

Created by: Mailaender

First I'd like to point out that the https://dsharpplus.github.io/articles/basics/first_bot.html tutorial no longer works. According to the API documentation you need DiscordIntents.Guild​Messages for the message handler to fire.

After I figured that out, I now get a crash that I don't understand. This may be a problem in my code which is based on https://github.com/DSharpPlus/Example-Bots/tree/master/DSPlus.Examples.CSharp.Ex01 so I attached it. I used version 4.0.1 via NuGet.

System.InvalidOperationException: Nullable object must have a value.
   at System.Nullable`1.get_Value()
   at DSharpPlus.DiscordClient.UpdateUser(DiscordUser usr, Nullable`1 guildId, DiscordGuild guild, TransportMember mbr)
   at DSharpPlus.DiscordClient.UpdateMessage(DiscordMessage message, TransportUser author, DiscordGuild guild, TransportMember member)
   at DSharpPlus.DiscordClient.PopulateMessageReactionsAndCache(DiscordMessage message, TransportUser author, TransportMember member)
   at DSharpPlus.DiscordClient.OnMessageCreateEventAsync(DiscordMessage message, TransportUser author, TransportMember member, TransportUser referenceAuthor, TransportMember referenceMember)
   at DSharpPlus.DiscordClient.HandleDispatchAsync(GatewayPayload payload)
   at DSharpPlus.DiscordClient.HandleSocketMessageAsync(String data)
   at DSharpPlus.DiscordClient.<InternalConnectAsync>g__SocketOnMessage|365_1(IWebSocketClient sender, SocketMessageEventArgs e)

Steps to reproduce

1. Connect this bot
2. Type ping in the chat.

namespace DiscordBot
{
    public class Program
    {
        readonly EventId eventId = new EventId(42, "Bot");

        DiscordClient client;

        public static void Main(string[] args)
        {
            var prog = new Program();
            prog.RunBotAsync().GetAwaiter().GetResult();
        }

        public async Task RunBotAsync()
        {
            var json = "";
            using (var fileStream = File.OpenRead("config.json"))
            using (var streamReader = new StreamReader(fileStream, new UTF8Encoding(false)))
                json = await streamReader.ReadToEndAsync();

            var configJson = JsonConvert.DeserializeObject<ConfigJson>(json);
            var config = new DiscordConfiguration
            {
                Token = configJson.Token,
                TokenType = TokenType.Bot,
                Intents = DiscordIntents.Guild​Messages,

                AutoReconnect = true,
                MinimumLogLevel = LogLevel.Information
            };

            client = new DiscordClient(config);

            client.Ready += ClientReady;
            client.GuildAvailable += GuildAvailable;
            client.ClientErrored += ClientError;

            await client.ConnectAsync();

            client.MessageCreated += MessageHandler;

            await Task.Delay(-1);
        }

        Task ClientReady(DiscordClient sender, ReadyEventArgs e)
        {
            sender.Logger.LogInformation(eventId, "Client is ready to process events.");

            return Task.CompletedTask;
        }

        Task GuildAvailable(DiscordClient sender, GuildCreateEventArgs e)
        {
            sender.Logger.LogInformation(eventId, $"Guild available: {e.Guild.Name}");

            return Task.CompletedTask;
        }

        Task ClientError(DiscordClient sender, ClientErrorEventArgs e)
        {
            sender.Logger.LogError(eventId, e.Exception, "Exception occured");

            return Task.CompletedTask;
        }

        Task MessageHandler(DiscordClient sender, MessageCreateEventArgs args)
        {
            if (args.Message.Content.ToLower().StartsWith("ping"))
                args.Message.RespondAsync("pong!");

            return Task.CompletedTask;
        }
    }

    public struct ConfigJson
    {
        [JsonProperty("token")]
        public string Token { get; private set; }

        [JsonProperty("prefix")]
        public string CommandPrefix { get; private set; }
    }
}

I believe this is nulling something in library.