avatar.js Cannot send an empty message

        throw new DiscordAPIError.DiscordAPIError(data, "code" in data ? data.code : data.error, status, method, url, requestData);
              ^

DiscordAPIError[50006]: Cannot send an empty message

        throw new DiscordAPIError.DiscordAPIError(data, "code" in data ? data.code : data.error, status, method, url, requestData);
              ^

DiscordAPIError[50006]: Cannot send an empty message

        const avatarList = message.mentions.users.map(user => {
            return `L'avatar de ${user.username} est : ${user.displayAvatarURL({ format: 'png' })}`;
        });
        message.channel.send(avatarList);

        const avatarList = message.mentions.users.map(user => {
            return `L'avatar de ${user.username} est : ${user.displayAvatarURL({ format: 'png' })}`;
        });
        message.channel.send(avatarList);