ServiceStack Error Loading WebHost Endpoint

Question

I'm trying to follow the Hello example of ServiceStack. I'm using Visual Studio 2010, Win 7 64-bit but IIS is configured to run 32-bit applications. The Hello project I created is using ASP.Net MVC3. I get this error trying to access the metadata:

Could not load type 'ServiceStack.WebHost.Endpoints.AppHostBase' from assembly 'ServiceStack, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.TypeLoadException: Could not load type 'ServiceStack.WebHost.Endpoints.AppHostBase' from assembly 'ServiceStack, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 


[TypeLoadException: Could not load type 'ServiceStack.WebHost.Endpoints.AppHostBase' from assembly 'ServiceStack, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.]
   System.Reflection.CustomAttribute._CreateCaObject(RuntimeModule pModule, IRuntimeMethodInfo pCtor, Byte** ppBlob, Byte* pEndBlob, Int32* pcNamedArgs) +0
   System.Reflection.CustomAttribute.CreateCaObject(RuntimeModule module, IRuntimeMethodInfo ctor, IntPtr& blob, IntPtr blobEnd, Int32& namedArgs) +46
   System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeModule decoratedModule, Int32 decoratedMetadataToken, Int32 pcaCount, RuntimeType attributeFilterType, Boolean mustBeInheritable, IList derivedAttributes, Boolean isDecoratedTargetSecurityTransparent) +529
   System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeAssembly assembly, RuntimeType caType) +103
   System.Reflection.RuntimeAssembly.GetCustomAttributes(Type attributeType, Boolean inherit) +64
   WebActivator.AssemblyExtensions.GetActivationAttributes(Assembly assembly) +145
   WebActivator.ActivationManager.RunActivationMethods() +216
   WebActivator.ActivationManager.RunPreStartMethods() +43
   WebActivator.ActivationManager.Run() +69

[InvalidOperationException: The pre-application start initialization method Run on type WebActivator.ActivationManager threw an exception with the following error message: Could not load type 'ServiceStack.WebHost.Endpoints.AppHostBase' from assembly 'ServiceStack, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'..]
   System.Web.Compilation.BuildManager.InvokePreStartInitMethods(ICollection`1 methods) +423
   System.Web.Compilation.BuildManager.CallPreStartInitMethods() +306
   System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +677

[HttpException (0x80004005): The pre-application start initialization method Run on type WebActivator.ActivationManager threw an exception with the following error message: Could not load type 'ServiceStack.WebHost.Endpoints.AppHostBase' from assembly 'ServiceStack, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'..]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +9089964
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +97
   System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr) +258

Answer 1

This is a very old post, but this might help someone if they received a similar error when developing against ServiceStack version 4.

There were some tweaks required to the Web.Config file if you decided to copy and paste from some servicestack guides that were written for ServiceStack version 3.

Http handler sections which has the ServiceStack.Webhost namespace will need to be changed to something like the following

  <httpHandlers>
    <add path="*" type="ServiceStack.HttpHandlerFactory, ServiceStack" verb="*"/>
  </httpHandlers>

  <handlers>
    <add path="*" name="ServiceStack.Factory" type="ServiceStack.HttpHandlerFactory, ServiceStack" verb="*" preCondition="integratedMode" resourceType="Unspecified" allowPathInfo="true" />        
  </handlers>

Hope it helps someone!

Answer 2

I ran into the same problem - when I created the Empty ASP.NET project I called it - aptly enough - ServiceStack. (Activation problem) When I updated my ASP project name (and all corresponding Namespaces) to something akin to ServiceStackExperiment - everything was unicorns and rainbows.