Question

Suddenly, I’ve started to get error in my ServiceStack MVC service application as below :

{"The given key was not present in the dictionary."}    
System.Exception {System.Collections.Generic.KeyNotFoundException}

and StackTrace:

  at System.ThrowHelper.ThrowKeyNotFoundException()
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at ServiceStack.WebHost.Endpoints.Utils.FilterAttributeCache.GetRequestFilterAttributes(Type requestDtoType) in C:\src\ServiceStack\src\ServiceStack\WebHost.Endpoints\Utils\FilterAttributeCache.cs:line 44
   at ServiceStack.WebHost.Endpoints.EndpointHost.ApplyRequestFilters(IHttpRequest httpReq, IHttpResponse httpRes, Object requestDto) in C:\src\ServiceStack\src\ServiceStack\WebHost.Endpoints\EndpointHost.cs:line 201
   at ServiceStack.WebHost.Endpoints.RestHandler.ProcessRequest(IHttpRequest httpReq, IHttpResponse httpRes, String operationName) in C:\src\ServiceStack\src\ServiceStack\WebHost.Endpoints\RestHandler.cs:line 79
   at ServiceStack.WebHost.Endpoints.Support.EndpointHandlerBase.ProcessRequest(HttpContext context) in C:\src\ServiceStack\src\ServiceStack\WebHost.Endpoints\Support\EndpointHandlerBase.cs:line 150
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

I’ve no idea about the error or what wrong is. My app was working and now not working.

Any idea how to fix this ?

EDIT 1: When I navigate the service url in my webbrowser,the debugger never reaches to my service classes and Run methods.

Answer 1

Well, quite strange!
Here are the actions I took and did not work.

• Restart IIS and VS 2010.
• Compile the code and debug on VS 2010.
• Compile the code and replace with the content on IIS and restart IIS again.

Here are the action I took and the project started to work again.

• Create a new MVC project.
• Install ServiceStack MVC via NuGet.
• Copy existing codes to new project.
• Rename the namespace in existing code on the new project.
• Debug on VS2010 and project started to work like a charm.

When I published the project to the the existing WebSite on IIS , I got the error below :

AppHost instance has been already set

However, to pass the error, I’ve deleted the existing website and created a new one.
Than, I’ve copied the new project output in the new website.

All started work like a charm again.

But I still don’t know why I got the errors.

I hope this will help who may have the same problems.