Bot joins voice channel, doesn't do anything.

So, I have the following code:

        public async Task JoinChannel(IVoiceChannel channel = null)
        {
            channel = channel ?? (Context.Message.Author as IGuildUser)?.VoiceChannel;

            if (channel == null)
            {
                await ReplyError("You need to be in a voice channel, or pass one as an argument.");
                return;
            }

            audioclient = await channel.ConnectAsync();
        }

When I run the bot and use a command to make it join a voice channel, it connects to that channel, but then it shows “A MessageReceived handler is blocking the gateway task.” (Warning), and eventually times out without completing ConnectAsync().

[Joe4evr]

You need to set RunMode = RunMode.Async in the Command attribute on all your commands that deal with voice. See here.

[CodeDiseaseDev]

But what if I use my own command handler? I can’t set RunMode then can I?