REST API - "The given key was not present in the dictionary."

Good day.

I am trying to create new leads via an API call.

I have the following settings configured inside postman:

URL: https://localhost/MyStoreInstance/entity/Default/20.200.001/Lead
HTTP method: PUT

Parameters:
$expand: Contact,Address
$select: Contact/FirstName,Contact/LastName,Address/Country

Headers:
Accept: application/json
Content-Type: application/json

Body:
{

"Contact":[{

"FirstName":{"value":"NewTest"},

"LastName":{"value":"NewTest"}

}],

"Address":{

"CountryID":{"value":"ZA"}

}

}


This is just a basic PUT method to make sure that it is working. I will later add it with correct and more values.

Any help would be greatly appreciated

I am receiving the following internal server error:
{
"message": "An error has occurred.",
"exceptionMessage": "The given key was not present in the dictionary.",
"exceptionType": "System.Collections.Generic.KeyNotFoundException",
"stackTrace": " at System.ThrowHelper.ThrowKeyNotFoundException()\r\n at System.Collections.Generic.Dictionary`2.get_Item(TKey key)\r\n at Microsoft.Data.OData.Query.SyntacticAst.ExpandBinder.GenerateExpandItem(ExpandTermToken tokenIn)\r\n at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()\r\n at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()\r\n at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)\r\n at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)\r\n at Microsoft.Data.OData.Query.SyntacticAst.ExpandBinder.Bind(ExpandToken tokenIn)\r\n at Microsoft.Data.OData.Query.SelectExpandSemanticBinder.Parse(IEdmEntityType elementType, IEdmEntitySet entitySet, ExpandToken expandToken, SelectToken selectToken, ODataUriParserConfiguration configuration)\r\n at PX.Api.ContractBased.OData.Helpers.ParseSelectCustomAndExpand(ODataUriParser uriParser, String select, String expand, String custom, IEdmEntityType elementType, EntityImpl entity, Nullable`1 returnBehaviorToSet, Boolean mapFilesByDefault)\r\n at PX.Api.ContractBased.OData.Helpers.FillRestQueryOptions(IEdmModel edmModel, EntityImpl entity, String filter, String select, String expand, String custom)\r\n at PX.Api.ContractBased.SystemContracts.V2.RestController.PutEntity(EntityImpl entity, String select, String filter, String expand, String custom)\r\n at lambda_method(Closure , Object , Object[] )\r\n at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass6_2.<GetExecutor>b__2(Object instance, Object[] methodParameters)\r\n at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__1.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__6.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__6.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.ActionFilterAttribute.<ExecuteActionFilterAsyncCore>d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__6.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__6.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.ActionFilterAttribute.<ExecuteActionFilterAsyncCore>d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__5.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Filters.AuthorizationFilterAttribute.<ExecuteAuthorizationFilterAsyncCore>d__3.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__6.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__6.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__15.MoveNext()"
}