It's pretty clear. It needs a public constructor that doesn't take parameters.


>Hi everybody,
>
>I could not figure out why I am getting this error
>
>

><Error>
><Message>An error has occurred.</Message>
><ExceptionMessage>
>An error occurred when trying to create a controller of type 'MatrixAttributesApiController'. 
>Make sure that the controller has a parameterless public constructor.
></ExceptionMessage>
><ExceptionType>System.InvalidOperationException</ExceptionType>
><StackTrace>
>at System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType) at 
>
>System.Web.Http.Controllers.HttpControllerDescriptor.CreateController(HttpRequestMessage request) at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()
></StackTrace>
><InnerException>
><Message>An error has occurred.</Message>
><ExceptionMessage>
>Type 'SysManager.Web.Areas.RetailInventory.Controllers.MatrixAttributesApiController' does not have a default constructor
></ExceptionMessage>
><ExceptionType>System.ArgumentException</ExceptionType>
><StackTrace>
>at System.Linq.Expressions.Expression.New(Type type) at System.Web.Http.Internal.TypeActivator.Create[TBase](Type instanceType) at 
>
>System.Web.Http.Dispatcher.DefaultHttpControllerActivator.GetInstanceOrActivator(HttpRequestMessage request, Type controllerType, Func`1& activator) at 
>
>System.Web.Http.Dispatcher.DefaultHttpControllerActivator.Create(HttpRequestMessage request, HttpControllerDescriptor controllerDescriptor, Type controllerType)
></StackTrace>
></InnerException>
></Error>

>
>I used our Scaffolding project to generate everything (Controller.cs, APIController.cs and all the front-end as well). I've done the same thing many times including one today very similar.
>
>But I can not figure out why I am getting the error and how to catch it and fix. Normally this error occurs if I forget to add binding in Ninject.config. But I didn't forget that.
>I also didn't forget to add mapping to AutoMapper.config although that error would appear later anyway.
>
>So, how exactly can I find out what is wrong this time?
>
>Thanks a lot in advance.