//Command
public async Task UserCrawl()
{
    List<SocketGuildUser> userList = new List<SocketGuildUser>();
    foreach (SocketGuildUser User in Context.Guild.Users)
    {
        Console.WriteLine($"Found user: {User.Username}#{User.Discriminator}");
        userList.Add(User);
    }
    foreach (SocketGuildUser user in userList)
    {
        Console.WriteLine($"Saving user: {user.Username}#{user.Discriminator}");
        Program.DatabaseHandler.AddNewProfile(user, false);
    }
}

//Create UserProfiles from users detected in the server
public void AddNewProfile(SocketGuildUser user, bool isBanned = false)
{
    UserProfile profile = new UserProfile(user, false);
    if (!UserProfiles.ContainsKey(user.Id)) UserProfiles.Add(user.Id, new UserProfile(user, false));
    SaveProfile(profile.GetSerializable());
}

//Serialize UserObject to JSON and write to file
private void SaveProfile(SerialUserProfile profile)
{
    try
    {
        JsonSerializerSettings settings = new JsonSerializerSettings();
        settings.PreserveReferencesHandling = PreserveReferencesHandling.Objects;
        settings.ReferenceLoopHandling = ReferenceLoopHandling.Serialize;
        if (!File.Exists($@"{userProfilePath}\{profile.UserSocket.Id.ToString()}.json"))
        {
            try
            {
                Console.WriteLine($"Serializing user: {profile.UserSocket.Username}#{profile.UserSocket.Discriminator}");
                File.WriteAllText($@"{userProfilePath}\{profile.UserSocket.Id.ToString()}.json", JsonConvert.SerializeObject(profile, settings)); //Error thrown here
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                throw;
            }
        }
    }
    catch (Exception e)
    {
        Console.WriteLine(e.Message);
    }
}

//UserProfile Object
public class UserProfile
{

    private List<UserWarning> UserWarnings { get; set; }
    private List<UserBan> UserBans { get; set; }
    private SocketGuildUser UserSocket { get; set; }
    private bool IsBanned { get; set; }

    public UserProfile(SocketGuildUser user, bool isBanned = false)
    {
        this.UserSocket = user;
        this.IsBanned = isBanned;
        this.UserWarnings = new List<UserWarning>();
        this.UserBans = new List<UserBan>();
        InitAsync();
    }

    private async Task InitAsync()
    {
        foreach (UserWarning warn in UserWarnings)
        {

        }
    }

    public List<UserWarning> GetUserWarnings()
    {
        return this.UserWarnings;
    }

    public List<UserBan> GetUserBans()
    {
        return this.UserBans;
    }

    public SocketGuildUser GetUserSocket()
    {
        return this.UserSocket;
    }

    public bool GetBanState()
    {
        return this.IsBanned;
    }

    public void AdduserBan(bool isHolderBan, Discord.Rest.RestUserMessage msg, SocketGuildUser user)
    {
        UserBan ban = new UserBan(DateTime.Now, UserSocket, new TimeSpan(42069), "Holding ban", isHolderBan, msg, user);
    }

    public SerialUserProfile GetSerializable()
    {
        SerialUserProfile profile = new SerialUserProfile();
        profile.IsBanned = GetBanState();
        profile.UserBans = GetUserBans();
        profile.UserSocket = GetUserSocket();
        profile.UserWarnings = GetUserWarnings();
        return profile;
    }
}

//version of UserProfile for serialization
public class SerialUserProfile
{
    public List<UserWarning> UserWarnings { get; set; }
    public List<UserBan> UserBans { get; set; }
    public SocketGuildUser UserSocket { get; set; }
    public bool IsBanned { get; set; }
}