Datei oder Assembly System.Web.WebPages.Razor, Version = 3.0.0.0 oder eine ihrer Abhängigkeiten konnte nicht geladen werden

Ich verwende MVC 5, WCF und Unity Framework in meiner Anwendung. 

Beim Ausführen des WCF-Dienstes wird eine Fehlermeldung angezeigt:

Server Error in '/' Application.

Could not load file or Assembly 'System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

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.FileNotFoundException: Could not load file or Assembly 'System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

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 'System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' 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: 


[FileNotFoundException: Could not load file or Assembly 'System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.]
   System.Web.Mvc.PreApplicationStartCode.Start() +0

[InvalidOperationException: The pre-application start initialization method Start on type System.Web.Mvc.PreApplicationStartCode threw an exception with the following error message: Could not load file or Assembly 'System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified..]
   System.Web.Compilation.BuildManager.InvokePreStartInitMethodsCore(ICollection`1 methods, Func`1 setHostingEnvironmentCultures) +556
   System.Web.Compilation.BuildManager.InvokePreStartInitMethods(ICollection`1 methods) +132
   System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +102
   System.Web.Compilation.BuildManager.ExecutePreAppStart() +153
   System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +516

[HttpException (0x80004005): The pre-application start initialization method Start on type System.Web.Mvc.PreApplicationStartCode threw an exception with the following error message: Could not load file or Assembly 'System.Web.WebPages.Razor, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified..]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +9882460
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +101
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +254

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.33440

Ich habe in WCF-Projekt System.Web.WebPages.Razor, Version = 3.0.0.0, hinzugefügt, der gleiche Fehler bleibt bestehen.

Kann jemand diesen Fehler beheben?