RESTful client in Unity - validation error - rest

Question

I have a RESTful server created with ASP.Net and am trying to connect to it with the use of a RESTful client from Unity. GET works perfectly, however I am getting a validation error when sending a POST request. At the same time both GET and POST work when sending requests from Postman.
My Server:
[HttpPost]
public IActionResult Create(User user){
Console.WriteLine("***POST***");
Console.WriteLine(user.Id+", "+user.sex+", "+user.age);
if(!ModelState.IsValid)
return BadRequest(ModelState);
_context.Users.Add(user);
_context.SaveChanges();
return CreatedAtRoute("GetUser", new { id = user.Id }, user);
}
My client:
IEnumerator PostRequest(string uri, User user){
string u = JsonUtility.ToJson(user);
Debug.Log(u);
using (UnityWebRequest webRequest = UnityWebRequest.Post(uri, u)){
webRequest.SetRequestHeader("Content-Type","application/json");
yield return webRequest.SendWebRequest();
string[] pages = uri.Split('/');
int page = pages.Length - 1;
if (webRequest.isNetworkError || webRequest.isHttpError){
Debug.Log(pages[page] + ":\nReceived: " + webRequest.downloadHandler.text);
}
else{
Debug.Log(pages[page] + ":\nReceived: " + webRequest.downloadHandler.text);
}
}
}
I was trying both with the Json conversion and writing the string on my own, also with the WWWForm, but the error stays.
The error says that it's an unknown HTTP error. When printing the returned text it says:
"One or more validation errors occurred.","status":400,"traceId":"|b95d39b7-4b773429a8f72b3c.","errors":{"$":["'%' is an invalid start of a value. Path: $ | LineNumber: 0 | BytePositionInLine: 0."]}}
On the server side it recognizes the correct method and controller, however, it doesn't even get to the first line of the method (Console.WriteLine). Then it says: "Executing ObjectResult, writing value of type 'Microsoft.AspNetCore.Mvc.ValidationProblemDetails'".
Here're all of the server side messages:
info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
Request starting HTTP/1.1 POST http://localhost:5001/user application/json 53
info: Microsoft.AspNetCore.Routing.EndpointMiddleware[0]
Executing endpoint 'TheNewestDbConnect.Controllers.UserController.Create (TheNewestDbConnect)'
info: Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker[3]
Route matched with {action = "Create", controller = "User"}. Executing controller action with signature Microsoft.AspNetCore.Mvc.IActionResult Create(TheNewestDbConnect.Data.Entities.User) on controller TheNewestDbConnect.Controllers.UserController (TheNewestDbConnect).
info: Microsoft.AspNetCore.Mvc.Infrastructure.ObjectResultExecutor[1]
Executing ObjectResult, writing value of type 'Microsoft.AspNetCore.Mvc.ValidationProblemDetails'.
info: Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker[2]
Executed action TheNewestDbConnect.Controllers.UserController.Create (TheNewestDbConnect) in 6.680400000000001ms
info: Microsoft.AspNetCore.Routing.EndpointMiddleware[1]
Executed endpoint 'TheNewestDbConnect.Controllers.UserController.Create (TheNewestDbConnect)'
info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
Request finished in 11.3971ms 400 application/problem+json; charset=utf-8
info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
I have no idea what is happening and how to solve it. Any help will be strongly appreciated!

Answer 1

Turned out I was just missing an upload handler. Adding this line solved it: webRequest.uploadHandler = new UploadHandlerRaw(System.Text.Encoding.UTF8.GetBytes(JsonObject));