Could not load file or assembly 'MvcSiteMapProvider

Question

I added the provider via nuget console Install-Package MvcSiteMapProvider.MVC4. The install looked good:

Successfully added 'MvcSiteMapProvider.MVC4 4.6.22' to XYZ.

When I execute the application I get this error message any suggestions on troubling shooting?

Server Error in '/XYZ' Application.

Could not load file or assembly 'MvcSiteMapProvider, Version=4.6.22.0, Culture=neutral, PublicKeyToken=1923abe4657913cc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) 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.IO.FileLoadException: Could not load file or assembly 'MvcSiteMapProvider, Version=4.6.22.0, Culture=neutral, PublicKeyToken=1923abe4657913cc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

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.

Assembly Load Trace: The following information can be helpful to determine why the assembly 'MvcSiteMapProvider, Version=4.6.22.0, Culture=neutral, PublicKeyToken=1923abe4657913cc' could not be loaded.

WRN: Assembly binding logging is turned OFF. To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1. Note: There is some performance penalty associated with assembly bind failure logging. To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].

Stack Trace:

[FileLoadException: Could not load file or assembly 'MvcSiteMapProvider, Version=4.6.22.0, Culture=neutral, PublicKeyToken=1923abe4657913cc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)] 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) +38 System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeModule decoratedModule, Int32 decoratedMetadataToken, Int32 pcaCount, RuntimeType attributeFilterType, Boolean mustBeInheritable, IList derivedAttributes, Boolean isDecoratedTargetSecurityTransparent) +571 System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeAssembly assembly, RuntimeType caType) +103 System.Reflection.RuntimeAssembly.GetCustomAttributes(Boolean inherit) +37 Owin.Loader.DefaultLoader.SearchForStartupAttribute(String friendlyName, IList1 errors, Boolean& conflict) +106 Owin.Loader.DefaultLoader.GetDefaultConfiguration(String friendlyName, IList1 errors) +46 Owin.Loader.DefaultLoader.LoadImplementation(String startupName, IList1 errorDetails) +75 Owin.Loader.DefaultLoader.Load(String startupName, IList1 errorDetails) +21 Microsoft.Owin.Host.SystemWeb.OwinBuilder.GetAppStartup() +115 Microsoft.Owin.Host.SystemWeb.OwinHttpModule.InitializeBlueprint() +28 System.Threading.LazyInitializer.EnsureInitializedCore(T& target, Boolean& initialized, Object& syncLock, Func`1 valueFactory) +115 Microsoft.Owin.Host.SystemWeb.OwinHttpModule.Init(HttpApplication context) +106 System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +534 System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +172 System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +352 System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +296

[HttpException (0x80004005): Could not load file or assembly 'MvcSiteMapProvider, Version=4.6.22.0, Culture=neutral, PublicKeyToken=1923abe4657913cc' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)] System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +9947380 System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +101 System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +261

Answer 1

Assuming you actually have the Nuget package installed, that error is most usually an issue with binding redirects in your Web.config. You can try to resolve the issue manually, by finding the appropriate binding redirect and making sure the version numbers are correct. I find it easier to just force remove the package and reinstall it. That will usually fix the problem:

> uninstall-package MvcSiteMapProvider.MVC4 -Force
> install-package MvcSiteMapProvider.MVC4

Make sure your Web.config is not open in your documents pane, or if it is, that you allow it to reload. If you save over it without refreshing from the filesystem after installing a Nuget package, you'll often bork things like binding redirects, leading to this issue.