Setting a channel topic

[keen wyvern]

ITextChannel Channel = _Client.GetChannel(Id) as ITextChannel;
                            await Channel.ModifyAsync(x =>
                            {
                                x.Topic = Message;
                            });

Is this still the correct way to set a topic? Nothing's happening and i copied this from the docs. I know the ID is correct cos I use the same part elsewhere and Message is never null in this situation.

[floral lagoon]

looks correct, what exactly is Message?