NullReferenceException

[ljf88]

Use Version：7.4.0

Source Class：
public class BaseResponse
{
   public string? TraceId { get; set; }
    public Guid InvoiceId { get; set; }
    public GatewayActionResultEnum ActionResult { get; set; }
    public string? ActionResultDescription { get; set; }
    public string? UniqueId { get; set; }
    public BaseRequest RawRequest { get; set; }
    public object RawResponse { get; set; }
    public dynamic? ResponseEntity { get; set; }
    public HttpStatusCode? StatusCode { get; set; }
    public List<Error> Errors { get; set; } = [];
    public bool IsRetry { get; set; }
}

public record Error(string Description, string? Code, string? Name);

public class PrepareResponse : BaseResponse
{
}

Target Class：
public class BaseRes
{
public Guid InvoiceId { get; set; }
public GatewayActionResultEnum ActionResult { get; set; }
public string? ActionResultDescription { get; set; }
public string? UniqueId { get; set; }
public object RawRequest { get; set; }
public string RawResponse { get; set; }
public dynamic? ResponseEntity { get; set; }
public bool IsFriendlyTip { get; set; } = false;
public string? FriendlyTip { get; set; }
public bool IsRetry { get; set; }
public string? TraceId { get; set; }
}

public class PrepareRes : BaseRes
{
    public Payment Payment { get; set; }
    public string? RedirectUrl { get; set; }
}

public partial class Payment
{
public Guid PaymentId { get; set; }
public string GatewayPayerId { get; set; } = null!;
public short? LastStatus { get; set; }
public DateTime CreateTime { get; set; }
public string GatewayPaymentId { get; set; } = null!;
public string Currency { get; set; } = null!;
public decimal Price { get; set; }
public string? Memo { get; set; }
public string GatewayPayerName { get; set; } = null!;
}

test data：
{"InvoiceId":"03f38e68-792a-48c0-a8ee-1d7877b2f7c9","ActionResult":1,"ActionResultDescription":null,"UniqueId":null,"RawRequest":null,"RawResponse":null,"ResponseEntity":null,"StatusCode":null,"Errors":[],"IsRetry":false,"TraceId":null}

call code：
source.Adapt(TypeAdapterConfig.GlobalSettings) ;
or
source.Adapt();

Error message："Object reference not set to an instance of an object."
StackTrack：" 在 Mapster.TypeAdapter.Adapt[TDestination](Object source, TypeAdapterConfig config)"

description：
When deleting the TraceId attribute in the baseResponse class or changing the TraceId attribute in the source and target classes from string? to string, the conversion works fine.

[ljf88]

Supplementary Description：
If you change the type of TraceId to e.g. int?, long?, the conversion is also normal